• Title/Summary/Keyword: environmental temperature

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EFFECT OF ENVIRONMENTAL TEMPERATURE ON HEAT PRODUCTION AND ITS ENERGY COST FOR THERMOREGULATION IN DAIRY HEIFERS

  • Purwanto, B.P.;Harada, M.;Yamamoto, S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.7 no.2
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    • pp.179-182
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    • 1994
  • A study was conducted using four dairy heifers to determine the effect of 10, 20 and $30^{\circ}C$ environmental temperatures on the physiological responses and heat production, at a fixed level of TDN intake ($60.5\;g/kg^{0.75}\;d$). The analysis showed significant affects of environmental temperature on respiration rate (RR), mean body temperature (Tb), changes in body heat storage (S) and heat production (HP). The HP at $20^{\circ}C$ was almost the same as at $10^{\circ}C$, but the HP at $30^{\circ}C$ was 11% higher than at $10^{\circ}C$. A tendency for an elongation of standing time (ST) with the increase in environmental temperature was also observed. These results suggest that the increase in energy cost of elongation of ST ($9.2\;kJ/kg^{0.75}\;d$) and $1.3^{\circ}C$ increase in Tb ($17.3\;kJ/kg^{0.75}\;d$).

A Study on the Wearing Comfort in Velvet Fabrics (Velvet 직물의 인체 착의 실험을 통한 착용감 연구)

  • Cho, Ji-Hyun;Ryu, Duck-Hwan;Lee, Yj-Ja
    • Korean Journal of Human Ecology
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    • v.5 no.2
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    • pp.123-130
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    • 1996
  • The purpose of this study is to examine and to evaluate the wearing performance of pile materials to produce velvet fabrics which have excellent wearing comfort. Acetate velvet, Cuprammonium rayon velvet were combined as textiles for clothing and acetate and viscose rayon were as textiles for lining at the environmental condition of temperature $15^{\circ}C,\;18^{\circ}C,\;21^{\circ}C,\;24^{\circ}C$, relative humidity $50{\pm}5%$ and air velocity 0.25 m/sec. Wearing comfort among 4 materials combinations(Aa, Av, Ra, Rv) was examined and compared. The results are as follows. The investigation of mean skin temperature for environmental temperature and material combinations showed that the mean temperature had a significant difference at the p<0.01 level in accordance with environmental temperature and material combinations.(Aa>Av>Ra>Rv) Moreover, in clothing climate only clothing temperature tended to increase almost linearly but at $24^{\circ}C$ there was no significant difference among textiles for lining compared with the other environmental temperatures. In subjective sensations thermal sensation and comfort sensation showed a significant difference in environmental temperatures and materials.(Aa>Av>Ra>Rv) Though a subject felt warmer, more humid, and more uncomfortable at $24^{\circ}C$ for all of the material combinations comparing with the other temperatures, there was no significant difference in materials.

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Forecasting the Effect of Global Warming on the Water Temperature and Thermal Stratification in Daecheong Reservoir (지구온난화가 대청호 수온 및 성층구조에 미치는 영향예측)

  • Cha, Yoon Cheol;Chung, Se Woong;Yoon, Sung Wan
    • Journal of Environmental Impact Assessment
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    • v.22 no.4
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    • pp.329-343
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    • 2013
  • According to previous studies, the increased air temperature can lead to change of thermal stratification structure of lakes and reservoirs. The changed thermal stratification may result in alteration of materials and energy flow. The objective of this study was to predict the effect of climate change on the water temperature and stratification structure of Daecheong Reservoir, located in Geum River basin of Korea, using a three-dimensional(3D) hydrodynamic model(ELCOM). A long-term(100 years) weather data set provided by the National Institute of Meteorological Research(NIMR) was used for forcing the 3D model. The model was applied to two different hydrological conditions, dry year(2001) and normal year(2004). It means that the effect of air temperature increase was only considered. Simulation results showed that the surface water temperature of the reservoir tend to increase in the future, and the establishment of thermal stratification can occur earlier and prolonged longer. As a result of heat flux analysis, the evaporative heat loss can increase in the future than now and before. However, the convective heat loss and net long wave radiation from water surface decreased due to increased air temperature.

Study on the Establishment of Threshold Criteria for Heat Health Watch Warning System in Korea; Part II: Improvement of Criteria (고온건강경보시스템 기준 설정에 관한 연구 ( II ) - 설정 기준 개선 -)

  • Jung, Woo-Sik;Park, Jong-Kil;Kim, Eun-Byul;Song, Jeong-Hui
    • Journal of Environmental Science International
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    • v.18 no.7
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    • pp.781-796
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    • 2009
  • The current standard level of Heat Health Watch Warning System consider both daily maximum temperature and daily maximum heat index(HI), but current standard could not consider daily maximum HI due to the difficulties in forecasting when we consider both daily maximum temperature and daily maximum HI and no considering HI because relative humidity could not observed for some regions. So, Newly established standard level of Heat Health Watch Warning System is based on daily maximum temperature exceeding $30^{\circ}C$ for two consecutive days or daily minimum temperature exceeding $25^{\circ}C$ and daily maximum temperature exceeding $30^{\circ}C$. These days are called "extreme heat days". On extreme heat days, the standard of extreme heat advisory is based on daily maximum temperature among exceeding $32.7^{\circ}C$ and not exceeding $34.8^{\circ}C$, and extreme heat warning is based on daily maximum temperature exceeding $34.8^{\circ}C$. ANOVA analysis was carried out using the data of Seoul Metropolitan City in 1994 to check the robustness of the new standard level of Heat Health Watch Warning System from this study, in particular for mortality variable. The results reveal that the new standard specifies excess mortality well, showing significance level of 0.05 in the difference of excess mortality for each phase.

Evaluation of Temperature and Precipitation on Integrated Climate and Air Quality Modeling System (ICAMS) for Air Quality Prediction (대기질 예측을 위한 기후·대기환경 통합모델링시스템 (ICAMS)의 기온 및 강수량 예측 능력 평가)

  • Choi, Jin-Young;Kim, Seung-Yeon;Hong, Sung-Chul;Lee, Jae-Bum;Song, Chang-Keun;Lee, Hyun-Ju;Lee, Suk-Jo
    • Journal of Korean Society for Atmospheric Environment
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    • v.28 no.6
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    • pp.615-631
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    • 2012
  • This study provides an evaluation for capability of Integrated Climate and Air quality Modeling System (ICAMS) on future regional scale climate projection. Temperature and precipitation are compared between ground-level observation data and results of regional models (MM5) for the past 30 years over the Korean peninsula. The ICAMS successfully simulates the local-scale spatial/seasonal variation of the temperature and precipitation. The probability distribution of simulated daily mean and minimum temperature agree well with the observed patterns and trends, although mean temperature shows a little cold bias about $1^{\circ}C$ compared to observations. It seems that a systematic cold bias is mostly due to an underestimation of maximum temperature. In the case of precipitation, the rainfall in winter and light rainfall are remarkably simulated well, but summer precipitation is underestimated in the heavy rainfall phenomena of exceeding 20 mm/day. The ICAMS shows a tendency to overestimate the number of washout days about 7%. Those results of this study indicate that the performance of ICAMS is reasonable regarding to air quality predication over the Korean peninsula.

Factors Affecting Ambient Monoterpene Levels in a Pine Forest

  • Kim, Jo-Chun;Kim, Ki-Hyun
    • Journal of Environmental Science International
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    • v.11 no.8
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    • pp.811-818
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    • 2002
  • The concentration levels of monoterpenes, including ${\alpha}$- and ${\beta}$-pinene, were measured in a pine forest in Florida, USA, over about one year. Based on this measurement data, the current study then investigated the factors affecting the environmental behavior of monoterpenes. Despite a moderately weak temperature variability in the study area, the temperature dependence of the concentration variations was still evident. The concentrations of the two pinenes were significantly affected by changes in the air temperature, as indicated by strong correlations with temperature. A close relation among the measured parameters was also found between the ${\beta}$-pinene and ozone concentrations, which is also in line with previous findings from other studies. In addition, it was interesting to note that the ${\beta}$/${\alpha}$ pinene concentration ratio exhibited a strong inverse correlation to temperature, with the seasonal mean ranging from 0.51(summer) to 0.93(winter). Accordingly, the current results indicate that, in a forest environment, the major terpene species concentrations are affected by both meteorological conditions and chemical reactions.

Environmental Factor Analysis Affecting Fruit Weight of Korean Melon (참외 과중에 영향을 미치는 환경요인 분석)

  • Choi, Don-Woo;Do, Han-Woo;Choi, Hong-Gip;Ryu, Young-Hyun;Lim, Cheong-Ryong
    • Journal of Korean Society of Rural Planning
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    • v.27 no.2
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    • pp.43-48
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    • 2021
  • In this study, an analysis was performed using the growth data and environment data of Korean melon farmers to confirm the influence of environmental factors variables on fruit weight of Korean melon. The analysis results can be summarized as follows. First, it was confirmed that humidity and temperature were recognized as the most important factors among the core factors of korean melon farm production management. Second, The correlation analysis of fruit weight and environmental factors showed a statistically significant soil temperature, internal humidity. Third, The Pooled OLS model estimation results showed that the estimation coefficient for soil temperature is (-), and the estimation coefficient for soil temperature square is (+), indicating that optimal control temperature exists.

A Study on the Tailoring of High / Low Temperature Test for KT-1 Trainer Export Version (수출형 KT-1 훈련기 고/저온 환경시험절차 적합화 연구)

  • Kim, Jin Seog
    • Journal of the Korean Society of Systems Engineering
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    • v.16 no.2
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    • pp.78-86
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    • 2020
  • The environmental tests are one of the key branches of the reliability tests. The purpose of the high/low environmental test of KT-1 Export Version Trainer is not only based on meeting the compliance of the reliability, customer satisfaction, but also for the expansion of its export. Amongst many existing environmental tests, the high and low temperature tests are considered as the two most important tests. The tests are considered and tailored to the high and low temperature methods of MIL-STD-810H. This paper proposes the tailoring processes and the results of High/Low temperature conditions, test procedures, and test profiles for the aircraft. Additionally, this paper is described by considering the view of MIL-STD-810H.

Impact of High-Resolution Sea Surface Temperatures on the Simulated Wind Resources in the Southeastern Coast of the Korean Peninsula (고해상도 해수면온도자료가 한반도 남동해안 풍력자원 수치모의에 미치는 영향)

  • Lee, Hwa-Woon;Cha, Yeong-Min;Lee, Soon-Hwan;Kim, Dong-Hyeok
    • Journal of Environmental Science International
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    • v.19 no.2
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    • pp.171-184
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    • 2010
  • Accurate simulation of the meteorological field is very important to assess the wind resources. Some researchers showed that sea surface temperature (SST) plays a leading role on the local meterological simulation. New Generation Sea Surface Temperature (NGSST), Operational Sea Surface Temperature and Sea Ice Analysis (OSTIA), and Real-Time Global Sea Surface Temperature (RTG SST) have different spatial distribution near the coast and OSTIA shows the best accuracy compared with buoy data in the southeastern coast of the Korean Peninsula. Those SST products are used to initialize the Weather Research and Forecasting (WRF) Model for November 13-23 2008. The simulation of OSTIA shows better result in comparison with NGSST and RTG SST. NGSST shows a large difference with OSTIA in horizontal and vertical wind fields during the weak synoptic condition, but wind power density shows a large difference during strong synoptic condition. RTG SST shows the similar patterns but smaller the magnitude and the extent.

Impact of UV Radiation and Elevated Temperature on Growth of Phytoplanktons, P. micans, and S. costatum

  • Lee, Bong-Hun;Park, Heung-Jai;Park, Won-Woo;Kim, Woo-Seong
    • Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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    • v.3 no.3
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    • pp.197-201
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    • 1999
  • The growth of two phytoplanktons was studied in a natural environment and in the laboratory under artificial radiation conditions in the presence or absence of UV radiation. The effect of an elevated temperature on the two phytoplanktons was also examined. UV radiation resulted in a decrease in the growth of the two phytoplanktons ; P. micans was more affected by UV than S. costatum. Four hours of UV radiation decreased the motility of S. costatum and P. micans by 20% and 40%, respectively. Accordingly, an elevated temperature and UV radiation decreased the growth rate of the two phytoplanktons investigated.

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