• Title/Summary/Keyword: minimum relative humidity

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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 Correlation of Outdoor Environmental Condition about Cooling Load (냉방부하에 영향을 미치는 외기 환경조건의 상관관계에 관한 연구)

  • Lee, Je-Myo
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.24 no.11
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    • pp.759-766
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    • 2012
  • To estimate the cooling load for the following day, outdoor temperature and humidity are needed in hourly base. But the meteorological administration forecasts only maximum and minimum temperature. New methodology is proposed for predicting hourly outdoor temperature and humidity by using the forecasted maximum and minimum temperature. The correlations for normalized outdoor temperature and specific humidity has been derived from the weather data for five years at Seoul, Daejeon and Pusan. The correlations for normalized temperature are independent of date, while the correlations for specific humidity are linearly dependent on date. The predicted results show fairly good agreement with the measured data. The prediction program is also developed for hourly outdoor dry bulb temperature, specific humidity, dew point, relative humidity, enthalpy and specific volume.

Spatiotemporal Changes of Temperature and Humidity in Lentinula edodes Cultivation Sheds (표고시설재배사내 시·공간적인 온·습도변화)

  • Ryu, Sung Ryul;Koo, Chang Duck
    • Journal of Korean Society of Forest Science
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    • v.94 no.6
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    • pp.468-475
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    • 2005
  • To understand spatiotemporal changes of temperature and humidity in Lentimula edodes cultivation sheds, temperature, relative humidity were measured with HOBO H8 series sensors in log cultivation sheds and sawdust cultivation sheds. The results obtained from October in 2003 to October in 2004 were as follows; 1. Horizontal temperature changes were smaller at center of cultivation shed inside than comer of cultivation shed inside, while relative humidity changes were greater about 3% at center of cultivation shed inside than corner of cultivation shed inside. 2. Vertical temperature changes showed that the temperature was higher at above than at below when the temperature rises, while the temperature was lower at above than at below when the temperature falls. Thus close to soil surface temperature showed a little fluctuation. Vertical relative humidity changes showed that the relative humidity was lower at above than at below when the temperature rises, while the relative humidity was higher at above than at below when the temperature falls. After all temperature and relative humidity was the opposite in cultivation shed. 3. It's showed in log cultivation shed that the minimum temperature was a subzero temperature until the end of April, while the minimum temperature did above zero after the beginning of the May. Besides a winter was the greatest at daily temperature range during the four season, about $30^{\circ}C$. On the other hand the minimum relative humidity was less than 20% at April, May and June but more than 40% after May.

A Study on Prediction of Temperature and Humidity for Estimation of Cooling Load (냉방부하 추정을 위한 온도와 습도 예측에 관한 연구)

  • Yoo, Seong-Yeon;Lee, Je-Myo;Han, Kyou-Hyun;Han, Seung-Ho
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.19 no.5
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    • pp.394-402
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    • 2007
  • To estimate the cooling load for the following day, outdoor temperature and humidity are needed in hourly base. But the meteorological administration forecasts only maximum and minimum temperature. New methodology is proposed for predicting hourly outdoor temperature and humidity by using the forecasted maximum and minimum temperature. The correlations for normalized outdoor temperature and specific humidity has been derived from the weather data for five years from 2001 to 2005 at Seoul, Daejeon and Pusan. The correlations for normalized temperature are independent of date, while the correlations for specific humidity are linearly dependent on date. The predicted results show fairly good agreement with the measured data. The prediction program is also developed for hourly outdoor dry bulb temperature, specific humidity, dew point, relative humidity, enthalpy and specific volume.

The Changes of Meteorological Environment by Urban Development (대규모 도시 재개발에 따른 기상환경변화)

  • Kim, Geun-Hoi;Kim, Yeon-Hee;Koo, Hae-Jung;Kim, Kyu-Rang;Jung, Hyun-Sook
    • Atmosphere
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    • v.24 no.1
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    • pp.69-76
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    • 2014
  • Urbanization affects the local thermal environment due to the large scale land use changes. To investigate the weather environment change of large scale urban redevelopment, 9 surface temperature and humidity observations were accomplished at Eunpyeong new town area. The observation period is from March 2007 to February 2010. In the center of development area, the air temperature has increased and relative humidity has decreased, by the changes of the land cover and building construction. In the area where the green zone is maintained, air temperature and relative humidity were not changed significantly. The air temperature and relative humidity for the other development observation stations is decreased and increased, respectively. The relative temperature difference between study area and a neighboring rural location was increased during observation periods. The difference is the highest during winter. The urban-rural minimum temperature difference was increased at development area, which means that urbanization affects increasing of minimum temperature in study area.

The Weather Characteristics of Frost Occurrence Days for Protecting Crops against Frost Damage (서리 피해 방지를 위한 서리 발생일의 기상 특성에 대한 연구)

  • Kwon, Young-Ah;Lee, Hyo-Shin;Kwon, Won-Tae;Boo, Kyung-On
    • Journal of the Korean Geographical Society
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    • v.43 no.6
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    • pp.824-842
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    • 2008
  • The main objective of the study was to analyze the weather conditions of frost occurrence for protecting crops against frost damage in Korea. The primary data used for the analysis of meteorological characteristics of frost occurrence days are the airmass pattern, minimum temperature, grass minimum temperature, daily temperature range, relative humidity, minimum relative humidity, mean wind speed in autumn and spring. Frost often occurs when the migratory anticyclone passes the southwest of Korea. The importance of grass minimum temperature measurements for agricultural purposes has previously been recognized. The grass minimum thermometer is capable of detecting ground frosts which are often not recorded by the minimum thermometer. The minimum temperature of frost occurrence days is above $0^{\circ}C$ in the coastal area, but the grass minimum temperature of frost occurrence days is below $0^{\circ}C$ in the whole area. The daily temperature of frost occurrence days is about 9 to $12^{\circ}C$ in the coastal area and is over $14^{\circ}C$ in the inland area. The minimum relative humidity of frost occurrence days is about 30 to 50%. The mean wind speed of frost occurrence days is less than 2m/sec.

Effect of Phenolic Resin According to Relative Humidity on Submerged Entry Nozzle with ZrO2-C System in Fabrication Process (ZrO2-C계 침지노즐 제조시 상대습도에 따른 바인더용 페놀수지의 영향)

  • Yoon, Sang-Hyeon;Kim, Jang-Hoon;Kim, Ju-Young;Lee, Hee-Soo;Koo, Young-Seok
    • Journal of the Korean Ceramic Society
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    • v.48 no.4
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    • pp.293-297
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    • 2011
  • The thermodynamic behavior of phenolic resin was investigated to verify the relation between the properties of porous ceramics with $ZrO_2$-C system for submerged entry nozzle and the characteristics of phenolic resin with various relative humidity. The green and the sintered density were decreased between 25% and 50% relative humidity, whereas they were gradually enhanced above 50% relative humidity. The highest value of apparent porosity was 20.1% and the minimum compressive strength was 69MPa in the specimen using the powder exposed to 50% relative humidity. As a result of thermal analysis for phenolic resin, the shift of endothermic peak to low temperature and the reduction of exothermic peak were observed, and the peaks corresponded to melting and curing of phenolic resin, respectively. The melting and the curing of phenolic resin generate the change of green density, and it can affect the properties of submerged entry nozzle.

The Effects of Climate Elements on Heat-related Illness in South Korea (기후요소가 온열질환자수에 미치는 영향)

  • Jeong, Daeun;Lim, Sook Hyang;Kim, Do-Woo;Lee, Woo-Seop
    • Journal of Climate Change Research
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    • v.7 no.2
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    • pp.205-215
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    • 2016
  • The relationship between the climate and the number of heat-related patients in South Korea was analysed in this study. The number of the patients was 1,612 during the summer 2011 to 2015 according to the Heat-related Illness (HRI) surveillance system. The coefficient of determination between the number of the patients and the daily maximum temperature was higher than that between the number of them and the other elements: the daily mean/minimum temperature and relative humidity. The thresholds of daily maximum and minimum temperature in metropolitan cities (MC) were higher than those in regions except for MC (RMC). The higher the maximum and minimum temperature became, the more frequently the heat-related illness rate was observed. The regional difference of this rate was that the rate in RMC was higher than that in MC. Prolonged heat wave and tropical night tended to cause more patients, which continued for 20 days and 31 days of maximum values, respectively. On the other hand, the relative humidity was not proportional to the number of the patients which was rather decreasing at over 70% of relative humidity.

Statistical Analysis on the Temperature Dependence and Long-Term Change of Relative Humidity Sensors (상대습도계의 온도 의존성과 경년변화의 통계적 분석)

  • Kim, Jong Chul;Choi, Byung Il;Woo, Sangbong;Yang, Inseok
    • Journal of Sensor Science and Technology
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    • v.21 no.6
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    • pp.420-424
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    • 2012
  • We have investigated temperature dependence and long-term change of humidity measurement from 32 relative humidity sensors. The readings of the humidity sensors depended not only the reference humidity, but also temperature of the chamber. Approximately, the temperature dependence of the humidity sensor in average was 0.05 %R.H./$^{\circ}C$ in the temperature range from $5^{\circ}C$ to $55^{\circ}C$. For humidity sensors that have an internal temperature compensation circuit, the resulting temperature dependence was weaker by 20%. It should be also noted that for the humidity sensors used in this work underwent ${\pm}3$ %R.H. change per year for level of confidence of 95%. The users of relative humidity sensors may refer this value as a minimum change when they set the calibration interval of the humidity sensors.

Influence of Weather Factors on the Incidence of the Mulberry Aleyrodid, Dialeuropora decempuncta (Quaintance and Baker) and Their Relation to Yield Loss

  • Bandyopadhyay U. K.;Santhakumar M. V.;Sahu P. K.;Saratchandra B.
    • International Journal of Industrial Entomology and Biomaterials
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    • v.11 no.2
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    • pp.129-133
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    • 2005
  • The seasonal occurrence and influence of abiotic factors viz., maximum and minimum temperature, maximum and minimum humidity and rainfall on population fluctuation of aleyrodid, Dialeuropora decempuncta on a evolved mulberry (Morus alba L.) variety known to be susceptible to aleyrodid infestation was assessed during the period from 1999 - 2001 in twenty-five villages under nine blocks of Malda district of West Bengal. The results indicate that the aleyrodid population is practically very low or absent during January to June and thereafter increases gradually. The increase in population of various stages of aleyrodid is significantly correlated with increase in previous 7 days of average maximum relative humidity.