• Title, Summary, Keyword: Temperature

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Projected Climate Change Impact on Surface Water Temperature in Korea (기후변화에 따른 지표수의 수온 영향평가)

  • Ahn, Jong Ho;Han, Dae Ho
    • Journal of Korean Society on Water Environment
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    • v.26 no.1
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    • pp.133-139
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    • 2010
  • Global human activities associated with the use of fossil fuels have aggravated climate change, increasing air temperature. Consequently, climate change has the potential to alter surface water temperature with significant impacts on biogeochemical cycling and ecosystems in natural water body. In this study, we examined temporal trends on historical records of surface water temperature, and investigated the air temperature/water temperature relationship and the potential water temperature change from an air temperature scenario developed with regional climate model. Although the temporal trends of water temperature are highly variable site-by-site, surface water temperature was highly dependent on air temperature, and has increased significantly in some sub-watersheds over the last two decades. The results presented here demonstrate that water temperature changes are expected to be slightly higher in river system than reservoir systems and more significant during winter than summer for both river and reservoir system. Projected change of surface water temperature will likely increase $1.06^{\circ}C$ for rivers and $0.95^{\circ}C$ for reservoirs during the period 2008 to 2050. Given the potential climatic changes, every $1^{\circ}C$ increase in water temperature could cause dissolved oxygen levels to fall every 0.206 ppm.

Design of CMOS Temperature Sensor Using Ring Oscillator (링발진기를 이용한 CMOS 온도센서 설계)

  • Choi, Jin-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.19 no.9
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    • pp.2081-2086
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    • 2015
  • The temperature sensor using ring oscillator is designed by 0.18㎛ CMOS process and the supply voltage is 1.5volts. The temperature sensor is designed by using temperature-independent and temperature-dependent ring oscillators and the output frequency of temperature-independent ring oscillator is constant with temperature and the output frequency of temperature-dependent ring oscillator decreases with increasing temperature. To convert the temperature to a digital value the output signal of temperature-independent ring oscillator is used for the clock signal and the output signal of temperature-dependent ring oscillator is used for the enable signal of counter. From HSPICE simulation results, the temperature error is less than form -0.7℃ to 1.0℃ when the operating temperature is varied from -20℃ to 70℃.

Effectsd of posture on physiological thermal responses with Ondol heating system (온돌난방에서의 자세에 따른 온열생리적 반응의 성차)

  • 신정화;최정화
    • Journal of the Korean Society of Clothing and Textiles
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    • v.22 no.8
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    • pp.1020-1031
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    • 1998
  • This study was done to investigate thermal reponses and to obtain the basic information of thermal comfort by sex and posture under the Ondol heating system. Six healthy males and females were exposed to Ondol(Room Temp.: 25$\pm$1$^{\circ}C$, 50$\pm$10%R.H, Floor Temp.:30$\pm$1$^{\circ}C$) on the of posture such as sitting, lying aside and supine on the floor for 30 minutes after 30 minutes' control phase. During the experiment, rectal temperature, skin temperature of 10 areas, local sweating rate, clothing microclimate, subjective sensation were measured. Rectal temperature gradually decreased and mean skin temperature grad-ually increased both male and female in any posture. There was not significant difference between male and female in rectal temperature and mean skin temperature. There were significant difference among the postures in rectal temperature(p<0.001) and mean skin temperature(p<0.001). In lying aside and supine on the floor, appearances of change and changes in rectal temperature and mean skin temperature were large, changes of weight were small. In sitting on the floor, appearances of change and changes in rectal temperature and mean skin temperature were small, changes of weight were large. The trunk skin tem-perature was higher in female than in male, but the extremity skin temperature was higher in male than in female. In sitting on the floor, foot skin temperature(p<0.001) was higher than any other local skin temperature. In supine on the floor, back skin temperature(p<0.001) was higher than any other local skin temperature.

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Development of Compensation-Type Fire Detector Using Metal-Insulator-Transition Critical-Temperature Sensor (금속-절연체 전이 임계온도센서를 이용한 보상식 화재 감지기 개발)

  • Jung, Sun-Kyu;Kim, Hyun-Tak
    • Fire Science and Engineering
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    • v.28 no.1
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    • pp.26-30
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    • 2014
  • A Compensation-type fire detector (CFD) is operated with two functions of a differential-temperature detector and as a fixed-temperature detector. The differential-temperature detector observes a rate of temperature increase, and the fixed-temperature detector measures a given fixed temperature. The differential-temperature detector does not observe the outbreak of fire in slowly increasing temperature conditions, whereas the fixed-temperature detector is not able to observe the outbreak of fire in conditions under predetermined temperature level. We developed a CFD to compensate for weaknesses of both detectors. To compensate for the disadvantages, a sensor of the sensor metal-insulator-transition critical-temperature sensor was used. Temperature coefficient of resistance is the sensitivity for sensor. At $55^{\circ}C$, temperature coefficient of resistance of metal-insulator-transition critical-temperature sensor was 14.15%. Temperature coefficient of resistance of thermistor was about 0.5%. This CFD was operated as two ways that fixed-temperature detector and differential-temperature detector in one sensor.

Study on the Climate Change and the Urbanization Effect in Busan (부산의 도시기후 변화 경향과 도시화 효과에 관한 연구)

  • Park, Myung-Hee;Lee, Joon-Soo;Ahn, Ji-Suk;Shu, Young-Sang;Han, In-Seng;Kim, Hae-Dong
    • Journal of Environmental Science International
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    • v.21 no.4
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    • pp.401-409
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    • 2012
  • This study examines the climatological variability of urban area and the increase of temperature by urbanization using the observed data of Busan and Mokpo during the last 100 years (1910~2010). The results are as follows. First, the maximum temperature in Busan during the last 100 years has increased by $1.5^{\circ}C$ while average temperature and the minimum temperature have increased by $1.6^{\circ}C$ and $2^{\circ}C$. In Mokpo, the maximum temperature and average temperature have increased by $1^{\circ}C$ and the minimum temperature has increased by $0.8^{\circ}C$. The increase of urban temperature appeared to be higher in Busan than in Mokpo by $0.5^{\circ}C{\sim}1.2^{\circ}C$. Second, as for the change in temperature before and after urbanization, the maximum temperature, average temperature and the minimum temperature during last 50 years compared to the previous 50 years have increased about $1.5^{\circ}C$, $1.6^{\circ}C$ and $2.1^{\circ}C$, however, the predicted temperature after removing urbanization effect was estimated to be increased by $1^{\circ}C$. The proportion that urbanization takes on the overall increase of temperature appeared to be 33% at the maximum temperature, 37.5% at average temperature and 52.3% at the minimum temperature, thus the proportion of urbanization appeared to be maximized at the minimum temperature.

Development of Automatic Measurement of Body Temperature by Taking the Temperature of Milk while Milking in Dairy Cattle (젖소에서 유즙체온 측정을 이용한 체온 자동 측정 방법의 개발)

  • 김용준;한종현;이수영;한병성;김동원
    • Journal of Veterinary Clinics
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    • v.19 no.1
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    • pp.37-42
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    • 2002
  • To develop an automatic detecting system of body temperature of dairy cattle while milking, measurement of the temperature of mammary skin using three thermometers attached into the lining of teat cup was carried out for 23 dairy cattle, whereas measurement of the temperature of milk while milking was also performed for 263 animals. For the latter experiment, three thermometers were attached at 10cm(left and right) and 20 cm away from an individual milk collector on the milk transporting hose. Taking the rectal temperature was accompanied all the time for the experiments. The measurement of the temperature of mammary skin using teat cup was successful for 11 of 23 dairy cattle(47.8%) and the mean temperature was $33.5^{\circ}C$ with the mean difference of $5.2^{\circ}C$ from the mean rectal temperature. The measurement of the temperature of milk using the thermometers onto the milk transporting hose while milking was very successful , From 37.3 to $38.4^{\circ}C$ of rectal temperature, the temperature of milk was almost the same and from 38.5 to $39.5^{\circ}C$ of rectal temperature, the temperature of milk tended to be low with the difference of 0.1$^{\circ}C$. From 39.6 to $41^{\circ}C$ of rectal temperature, the temperature of milk tended to be low with the difference of $0.2-0.6^{\circ}C$. These results indicated that automatic detection of body temperature whether low or high can be possible if the temperature of milk is taken while milking and if it is connected to the integration system by on-line.

Analysis of unsteady temperature distribution in a cylinder for rifle barrel disign (원통형 용기의 비정상온도해석)

  • ;;;Lee, Hung Joo
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.3 no.4
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    • pp.173-180
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    • 1979
  • Temperature distriburion in a hollow chlinder has been analyzed mathematically. Unsteady condition considered assumed a constant heat flux input from the inside. The results are compared with experimental results of surface temperature rise of a gun barrel during continuous firing. Their agreements are acceptable. Effects of various dimensionless parameters on the surface temperature rise are discussed. For small Biot numbers, the external survface temperature approaches more rapidly to the steady temperature. Temperature difference between internal and external surfaces becomes greater for small Biot number. Steady solution assumed that the gas temperature inside the cylinder varies periodically. Relative amplitude and phase angles between the gas temperature and the internal or external surface temperature are obtained. Phase angles become smaller for large radiancy of gas temperature variation, small external Biot number, or large internal biot number. Relative amplitudes become samller as radiancy of gas temperature variation and internal Biot number become smaller. or external Biot number becomes larger. The solution obtained in this paper can be applied to gun barrels, heat pipes used in heat excangers, and reciprocation engines.

Effects of Temperature and Daylength on Growth and Grain Yield in Wheat (T. aestivum) (온도 및 일장조건이 소맥의 생육 및 수량에 미치는 영향)

  • Cho, C.H.;Chung, T.Y.
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.24 no.2
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    • pp.35-41
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    • 1979
  • To observe the effects of temperature and photoperiod on the growth and yield of winter wheat (Triticum aestivum, L) eight varieties including Chang Kwang were tested at various treatments like longday-high temperature (24hrs-20\circ), shortdayhigh temperature (12hrs-20\circ), longday-low temperature (24hrs-14\circ) and shortday-low temperature (12hrs-14\circ). Among the traits measured, days to heading, plant height, spike length, number of spikes per hill and grain yield per hill were generally decreased at high temperature and long day treatment and increased at low temperature and shortday condition. Number of grains per spike was decreased at low temperature and short day condition while increased at longday and high temperature conditions. Grain weight was decreased significantly at high temperature and shortday while increased at low temperature and longday treatment.

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Effect of Feet Cooling and Feet Warming on the Behavioral Temperature Regulation (족부의 냉각과 가온이 행동성 체온조절에 미치는 영향)

  • Jeong, Woon-Seon
    • The Korean Journal of Community Living Science
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    • v.18 no.4
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    • pp.681-686
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    • 2007
  • This study was conducted to investigate the effects of the thermally different states of human feet on temperature regulation in winter season. Five healthy female students of age 20 volunteered as subjects to participate in the study. Physiological responses such as rectal temperature and skin temperatures as well as subjective responses of thermal comfort and thermal sensation were observed. Preferred clothing and preferred temperature were also evaluated in terms of behavioral temperature regulation. The results obtained through the experiment were statistically analyzed using paired t test. Rectal temperature was decreased greater (p<.01) and mean skin temperature was maintained higher (p<.01) in feet wanning than in feet cooling. Results of preferred clothing were coincident with those of general thermal sensation. There was a higher tendency to prefer temperature in feet wanning than feet cooling in the morning. It was concluded that keeping feet skin temperature lower in the early morning and higher in the late evening would be effective in terms of regulating circadian rhythm of core temperature.

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An Analysis of a Winter-time Temperature Change and an Extreme Cold Waves Frequency in Korea (우리나라의 겨울철 기온 변화 및 한파 발생빈도 분석)

  • Jeon, Mi Jeong;Cho, Yongsung
    • Journal of Climate Change Research
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    • v.6 no.2
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    • pp.87-94
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    • 2015
  • To compare changes in winter temperature over South Korea, 30-year average climate data and climate data of recent 10 years (2014~2014) such as mean temperature, daily maximum temperature and daily minimum temperature were analyzed. Also, we set analysis extreme cold waves frequency related to winter such as freezing days, snow days, days with temperature of below -5, and days with temperature of below -10. This process enabled the comparative analysis of winter temperature changes and extreme cold waves frequency related to winter. This study estimated that winter temperature has gradually increased throughout the last five decades, however, the frequency of extreme weather, such as cold waves has also increased.