• 제목/요약/키워드: temperature and relative humidity

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곡물빈용 공기조화장치의 퍼지제어기 개발 (Development of Fuzzy Controller for Air Conditioning of Grain Bin)

  • 최영수;문대식;정종훈
    • 한국식품저장유통학회지
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    • 제9권2호
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    • pp.137-143
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    • 2002
  • Temperature and humidity are the most important factors and should be effectively controlled for the cold storage of graius. Fuzzy logic can be easily implemented to the MIMO(Multi-Input Multi-Output) control systems. For the cold storage in grain bin, fuzzy logic was applied to an air conditioning system. The capacities of the grain bin and the air conditioner are 80 tons and 30㎾, respectively. Also, the target values of temperature and relative humidity in outlet duct of the air conditioner were 8$\^{C}$ and 75%, respectively. In order to control temperature and relative humidity of air, a damper in inlet duct was manipulated for temperature control and a heater was used for humidity control. Temperature deviation and change of temperature deviation were used as input parameters for the fuzzy system. Humidity was only considered as a load. The experimental results showed that the controlled temperature of exhausted air was maintained at 8$\pm$2$\^{C}$. Relative humidity of the air was also controlled at the target relative humidity of 50∼80%.

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

  • 박철우;박영훈;박용걸
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2008년도 추계학술대회 논문집
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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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간헐공조 전시관내 유물 진열장의 온·습도 환경 분석 (Analysis for Temperature and Relative Humidity of Showcase in Exhibition Hall Operated Intermittent Air Conditioning)

  • 이선명;임보아;김서진
    • 보존과학회지
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    • 제29권4호
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    • pp.311-320
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    • 2013
  • 조사 대상인 유물 진열장은 온도 변화에 대응한 조온기능이 미약한 반면 조습 능력이 비교적 높았다. 유물 진열장 내부의 연평균 온 습도는 $18.8^{\circ}C$, 60.3% 로 전시실에 비해 온도는 낮고 습도는 높은 분포를 나타냈다. 또한 온도는 계절변화에 따라 변동률이 높은 반면 습도는 계절별 평균값이 59~61%로 일정하게 유지되었다. 여름철에는 전시실과 마찬가지로 고온고습 분포를 나타냈고 공조기 가동에 따른 온도의 하강은 습도를 상승시켰으며. 겨울철에는 공조기 가동에 따라 전시실과 유물 진열장 간 온 습도의 차이가 커져 수분 문제가 제기되었다. 유물 진열장 내부 온 습도에 대한 PI는 18.0%로 전시물 보존을 위한 적정 온 습도 조성률이 매우 저조하였다. 특히 여름철과 겨울철은 PI가 1% 미만으로 진열장 내 철저한 온습도 관리가 필요할 것으로 판단된다.

담배 경도에 관한 연구(II) 상대습도, 온도 및 진충량이 담배의 경도에 미치는 영향 (Studies on the cigarette hardness(II) The Influence of relative humidity, temperature and net weight on cigarette hardness)

  • 정한주;민영근;김병구;김기환
    • 한국연초학회지
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    • 제13권1호
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    • pp.13-18
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    • 1991
  • This experiment carried out to review influence of relative humidity, temperature and net weight on cigarette hardness for the uniformal control of cigarette quality. Obtained results are as follows: 1. The difference in the cigarette physical properties of constant hardness control is considerably lower than that of constant net weight control. 2. Contribution rate for cigarette hardness is relative humidity > net weight > temperature. 3. The multiple regression equation of cigarette hardness related with relative humidity, temperature and net weight is calculated as follows.

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Effects of Curing Temperature on Autogenous Shrinkage, Relative Humidity, Pore Structure of Cement Pastes

  • Park Ki-Bong
    • 콘크리트학회논문집
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    • 제17권5호
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    • pp.853-856
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    • 2005
  • A low water/cement ratio leads to autogenous shrinkage of cement paste at an early age. This autogenous shrinkage is related to the change of relative humidity in the pore structure that is formed during the hydration process. The relationship between autogenous shrinkage and relative humidity change are relatively well defined today, but the effects of temperature on autogenous shrinkage, relative humidity, and pore structures have been studied less systematically. This study focused on correlating alterations of these properties of cement paste hydrated at constant temperatures of 20, 40, and $60^{\circ}C$. The test results clearly indicate that increasing curing temperature resulted in increased porosity, particularly for pores between 5 to 50 nm as measured by MIP, and increased autogenous shrinkages, as a consequence of a reduction of relative humidity at early ages.

The Effects of Micro-Environmental Factors on the House Dust Mite

  • Jo, Wan-Je;Sohn, Jang Yeul
    • Architectural research
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    • 제9권2호
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    • pp.37-45
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    • 2007
  • The proliferation of the House Dust Mite(HDM) is affected by temperature, humidity, ventilation, etc. Measuring temperature and humidity was performed at the very location where dust samplings take place and where they live in reality together with temperature and humidity of the ambient of the room. There has been discussion over the key environment factor of HDM survival; absolute humidity or relative humidity. It seems that relative humidity is the more important determinant for the mite's survival through the analysis of previous studies. Temperature, humidity, ventilation rate and Der P1 were measured in 4 flats in London. Mite allergen was detected in every house. Levels of Der P1 varied between <100ng/g and 22,778ng/g. Flats with high relative humidity(>50%) and poor ventilation(<0.5ach) showed higher levels of mite allergen than flats with lower humidity and adequate air change rate. Questionnaire survey was conducted and the result helped to confirm the findings from monitoring of environmental factors and the dust sampling.

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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    • 제17권2호
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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.

증발기의 압력강하에 대한 상대습도의 영향 (Effects of Relative Humidity on the Evaporator Pressure Drop)

  • 김창덕;강신형;박일환;이진호
    • 설비공학논문집
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    • 제16권5호
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    • pp.397-407
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    • 2004
  • It is well known that some key parameters, such as evaporating temperature, refrigerant mass flow rate, face velocity and inlet air temperature, have significant influence on the evaporator performance. However performance studies related to a humid environment have been very scarce. It is demonstrated that the refrigerant mass flow rate, heat flux, water condensing rate and air outlet temperature of the evaporator significantly increase with air inlet relative humidity. As the air inlet relative humidity increases, the latent and total heat transfer rates increase, but the sensible heat transfer rate decreases. The purpose of this study is to provide experimental data on the effect of air inlet relative humidity on the air and refrigerant side pressure drop characteristics for a slit fin-tube heat exchanger. Experiments were carried out under the conditions of inlet refrigerant saturation temperature of 7 $^{\circ}C$ and mass flux varied from 150 to 250 kg/$m^2$s. The condition of air was dry bulb temperature of 27$^{\circ}C$, air Velocity Varied from 0.38 to 1.6 m/s. Experiments Showed that air Velocity decreased 8.7% on 50% of relative humidity 40% of that at degree of superheat of 5$^{\circ}C$, which resulted that pressure drop of air and refrigerant was decreased 20.8 and 8.3% for 50% of relative humidity as compared to 40%, respectively.

수림의 계층구조가 녹지내의 기온 및 습도에 미치는 영향 (Forest Stratification Effect of Air Temperature and Humidity in the Green Space)

  • 윤용한
    • 환경생물
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    • 제21권2호
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    • pp.120-125
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    • 2003
  • 본 연구는 토지피복현황과 수림의 계층구조 등이 다양한 도시녹지를 대상으로 기온 및 급도에 미치는 영향물 점성 빛 정량적으로 파악하기 위해 녹지내의 기온 및 습도를 관측하였다. 그 데이터클 바탕으로 녹지내의 토지피복현황과 기온 및 습도분포, 녹지내의 수목그루와 녹적량및 습도와의 관련성을 회귀분석 둥에 의해 해석 하였다. 그 결과, 고온역은 인공구조물과 나지 주변에서, 저온역은 수림지와 수면 주변에서 형성되었다. 습도는 기온분포에 거의 대응하는 형태로 고온역이 저습역이고, 저온역이 고습역으로 나타났다. 또한, 수림의 계층구조가 2,3층으로 덮여 있는 구역과 수면을 핵으로 그 주변은 수림으로 둘러싸인 구역이 상대적으로 높은 습도를 나타냈다. 수루그루 빛 녹적량의 증가는 어떤 수고라도 습도의 상승에 효과적이고 그 효율은 교목, 소교목, 관루의 순이다.

The effect of temperature and relative humidity on concrete slab specimens with impressed current cathodic protection system

  • Jeong, Jin-A;Jin, Chung-Kuk
    • Journal of Advanced Marine Engineering and Technology
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    • 제37권3호
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    • pp.260-265
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    • 2013
  • Impressed current cathodic protection (ICCP) system is one of the most promising corrosion protection methods. The Effect of ICCP system can be changed at diverse conditions. Particularly, temperature and relative humidity plays a crucial role in CP (Cathodic Protection) effect. Thus, in this study, the influence of temperature and relative humidity on concrete specimens was investigated. Specimens were concrete slab type with a base of $400mm{\times}400mm$ and height of 70mm. To enhance the effect of CP system, seawater was used as an electrolyte. Used anode for ICCP system was mixed metal oxide (MMO) titanium. Test factors were natural potential, CP potential, CP current, and 4-hour depolarization potential. From this study, it could be confirm that CP potential and current were highly influenced by temperature and relative humidity.