• 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.

• 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.

• 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.

• 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%.

• 대기
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• 제31권3호
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• pp.295-309
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• 2021

Diurnal variations of air temperature and relative humidity in the Urban Canopy Layer (UCL) of the Seoul metropolitan area are examined using the Weather Research and Forecasting model coupled with the Seoul National University Urban Canopy Model. The canopy layer air temperature is higher than 2-m air temperature and exhibits a more rapid rise and an earlier peak in the daytime. These result from the multiple reflections of shortwave radiation and longwave radiation trapping due to the urban geometry. Because of the absence of vegetation in the UCL and the higher canopy layer air temperature, the canopy layer relative humidity is lower than 2-m relative humidity. Additional simulations with building height changes are conducted to examine the sensitivities of the canopy layer meteorological variables to the urban canyon aspect ratio. As the aspect ratio increases, net sensible heat flux entering the UCL increases (decreases) in the daytime (nighttime). However, the increase in the volume of the UCL reduces the magnitude of change rate of the canopy layer air temperature. As a result, the canopy layer air temperature generally decreases in the daytime and increases in the nighttime as the aspect ratio increases. The changes in the canopy layer relative humidity due to the aspect ratio change are largely determined by the canopy layer air temperature. As the aspect ratio increases, the canopy layer relative humidity is generally increased in the daytime and decreased in the nighttime, contrary to the canopy layer air temperature.

• 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.

• 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.

• 한국산림과학회지
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• 제94권6호
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• pp.468-475
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• 2005

표고재배사내 시공간적인 온습도 변화를 이해하기 위하여 표고시설재배사내 HOBO H8시리즈 센서를 이용하여 온 습도를 측정하였다. 2003년 10월부터 2004년 10월 까지 얻어진 결과는 다음과 같다. 1. 수평적 온도변화는 재배사내부의 가장자리보다 중앙부분이 더 작았다. 한편 상대습도변화 는 재배사내부의 가장자리보다 중앙부분에서 3%정도가 크게 나타났다. 2. 수직적 온도변화는 온도가 올라갈 때 하단 보다 상단에서 컷으며, 온도가 떨어질 때 하단 보다 상단에서 작았다. 그래서 토양표면에 가까울수록 온도는 작은 변동폭을 보였다. 수직적 상대습도변화는 온도가 올라갈 때 하단보다 상단에서 작았으며, 온도가 떨어질 때 는 하단보다 상단에서 컷다. 결국 온 습도는 재배사내에서 반대경향으로 나타났다. 3. 원목재배사내에서 최저온도는 4월말까지 영하의 온도로 유지되었으며, 최저온도는 5월초 에 비로서 영상온도를 회복하였다. 한편 계절별로 볼때 겨울이 온도변화가 가장 심했으며, 일중 $30^{\circ}C$를 나타냈다. 반면 최저상대습도로서 4월, 5월, 6월에 20%이하를 보였으며, 그 이 후 40%이상을 회복하였다.

• 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.

• 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.