• 제목/요약/키워드: Temperature difference

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가축에서 간이 체온측정 비접촉성 체온계 개발을 위한 임상적 연구 (Clinical Studies for the Development of Non-contact Thermometer to Take Easily the Body Temperature of Domestic Animals)

  • 김용준;이대영;한경호
    • 한국임상수의학회지
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    • 제20권3호
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    • pp.357-363
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    • 2003
  • These studies were carried out to develop non-contact thermometer to take easily the body temperature of domestic animals instead of taking rectal temperature. For the studies, 86 cattle, 57 horses, 72 pigs, 43 goats, and 42 dogs were used and body parts as neck, flank, axilla, lateral abdomen, gluteus, inguinal region, or jugular groove were chosen for taking temperature according to different species. Two types of commercial non-contact thermometers were used to take the temperature of certain body part and at the same time the rectal temperature using digital thermo-meter was taken to compare the difference of temperature between rectum and certain body part. The difference of mean temperature in cattle between rectum and axilla and flank were 0.52 and $2.41^{\circ}C$, respectively, using non-contact thermometer I, whereas $3.02^{\circ}C$ between rectum and flank using thermometer II. The difference of mean temperature in horses between rectum and axilla, gluteus, and jugular groove were 0.52, 1.49, and $0.26^{\circ}C$, respectively, using thermometer I, whereas 2.28 ane $0.92^{\circ}C$ between rectum and gluteus or jugular groove using thermometer II. The difference of mean temperature in swine between rectum and flank, inguinal region, and neck were 1.23, 0.21, and $0.8^{\circ}C$, respectively, using thermometer I, whereas 1.42, 0.711, and $1.25^{\circ}C$ using thermometer II The difference of mean temperature in goats between rectum and lateral abdomen and inguinal region were 1.02 and $0.12^{\circ}C$, respectively, using thermometer I, whereas 1.96 and $1.01^{\circ}C$ using thermometer II. The difference of mean temperature in dogs between rectum and lateral abdomen, inguinal region, and neck were 3.26, 0.24, and $2.37^{\circ}C$, respectively, using thermometer I, whereas 3.45, 0.56, and $2.61^{\circ}C$ using thermometer II.

액체 제습식 냉방 시스템의 최적 설계 (Optimization Design of Liquid Desiccant Cooling System)

  • 전동순;이상재;김선창;김영률;이창준
    • 설비공학논문집
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    • 제22권7호
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    • pp.419-428
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    • 2010
  • This paper presents the optimization process of liquid desiccant cooling system using LiCl aqueous solution as a working fluid. Operating conditions(mass flow rate, conditioner outlet concentration, difference concentration) and design factors for heat exchangers(difference temperature of the district heating water, leaving temperature difference of the conditioner, leaving temperature difference of the regenerator, air temperature difference of the conditioner, air temperature difference of the regenerator) were optimized by response surface method. As a result, we obtained the 7.297 kW of cooling capacity and 0.788 of COP at optimized condition. Effect of difference temperature of hot water on system performances was also examined. As difference temperature of the district heating water increases, the cooling capacity increases and COP decreases.

Time-Dependent Optimal Heater Control Using Finite Difference Method

  • Li, Zhen-Zhe;Heo, Kwang-Su;Choi, Jun-Hoo;Seol, Seoung-Yun
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2008년도 추계학술대회B
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    • pp.2254-2255
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    • 2008
  • Thermoforming is one of the most versatile and economical process to produce polymer products. The drawback of thermoforming is difficult to control thickness of final products. Temperature distribution affects the thickness distribution of final products, but temperature difference between surface and center of sheet is difficult to decrease because of low thermal conductivity of ABS material. In order to decrease temperature difference between surface and center, heating profile must be expressed as exponential function form. In this study, Finite Difference Method was used to find out the coefficients of optimal heating profiles. Through investigation, the optimal results using Finite Difference Method show that temperature difference between surface and center of sheet can be remarkably minimized with satisfying Temperature of Forming Window.

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온실작물의 관개계획의 수립을 위한 엽온의 활용 (Using Leaf Temperature for Irrigation Scheduling in Greenhouse)

  • 이남호;이훈선
    • 한국농공학회지
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    • 제43권6호
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    • pp.103-112
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    • 2001
  • The development of infrared thermometry has led many researchers to use plant temperatures, and specifically the temperature of the crop canopy in the field, for estimating the water stress of a crop. The purpose of this study was to evaluate the role of leaf temperature in irrigation scheduling. An experiment was carried out in a greenhouse with chinese cabbage. Leaf temperature was measured with infrared thermometry and evapotranspiration of the crop was measured by lysimeters. Influence of the difference between leaf temperature and air temperature on crop evapotranspiration was evaluated under varying water stress condition. A further objective was to evaluate the effect of other climatic variables on the relationship between evapotranspiration and temperature difference between leaf and air. A statistical model for estimating evapotranspiration using the temperature difference, relative humidity. and radiation was developed and tested. Crop water stress index was calculated using vapour pressure deficit and the temperature difference. Relations between the crop water stress index and crop evapotranspiration was tested. The index was closely related with evapotranspiration.

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온도차 및 부하 저항에 따른 열전모듈의 발전 특성 분석 (Experimental Study on the Power Generation of a Thermoelectric Module with Temperature Difference and Load Resistance)

  • 이공훈;김욱중;고득용
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2007년도 춘계학술대회B
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    • pp.1942-1947
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    • 2007
  • A thermoelectric module can be used for cooling or power generation. The basic requirements to achieve a significant thermoelectric performance are the same for both generators and coolers. Thermoelectric modules with $Bi_2Te_3$ materials are usually employed in the cooling applications below room temperature but it can also be used for the power generation in the similar temperature range. In the present study, the power generation with a $Bi_2Te_3$ thermoelectric module has been investigated. The temperature difference between the hot and cold sides of the module is maintained with electric heater and cold water from the circulating water bath. The result shows that the electric current generated increases with temperature difference and decreases with the load resistance. However, the voltage increases with both the temperature difference and load resistance. The electric power increases with temperature difference and it has the maximum value when the load resistance is about 4 ${\Omega}$ for a given device.

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도시 공원 내 식생 수관에 의한 기온 변화 (Air Temperature Change by Vegetation Canopy in Urban Park)

  • 이상화;이규석;정해연;김문성
    • 한국환경복원기술학회지
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    • 제12권1호
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    • pp.44-51
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    • 2009
  • In order to determine air temperature difference by canopy layer in the forest, air temperatures were observed at Seolleung Park, Gahngnam-ku, Seoul. from November 9, 2007 to November 8, 2008 by 10 minute interval. The data were analyzed in terms of diurnal variation based on annual and monthly temperature difference. Using calm, less cloudy and no rainy weather data, average air temperature difference between forest and grass was observed as $0.8^{\circ}C$. The maximum air temperature difference was observed at 22:10, 23:20, 23:30 and 23:40 by $2.13^{\circ}C$ and the minimum one observed at 13:00 by $-0.84^{\circ}C$ in diurnal variation. The maximum temperature difference occurred at 19 : 50 on September by $3.67^{\circ}C$, Overall the air temperature in the forest was higher than that of grass at night and lower in midday.

기능적인 하지길이 차이에 따른 족저압 변화가 족부체열에 미치는 영향 (The Foot Pressure Change Caused by Functional Leg Length Having an Effect on the Foot Temperature)

  • 김민주;김주연;이혜원;임주연;하현진;안진호
    • 대한통합의학회지
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    • 제1권2호
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    • pp.37-46
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    • 2013
  • Purpose : The purpose of the research was to analyze foot pressure, foot temperature, and correlation between foot pressure and foot temperature to grasp impact on foot pressure and body temperature distribution chart depending on functional difference of leg length. Method : After measuring leg length, put 15 students whose functional difference of leg length was over 10mm to difference group and 15 students whose functional difference of leg length was under 5mm to normal group and categorize soles of foot into 6 sections of hallux head, 1st metatarsal head, 2-4 metatarsal head, 5 metatarsal head, lateral heel, and then measure by foot pressure analyzer to analyze characteristic of pressure distribution and classify into front of the lower leg, back of the lower leg, soles of foot and measure by body temperature analyzer to analyze by checking body temperature. Result : Weight difference depending on foot pressure and body temperature was bigger when functional difference of leg length was bigger, and it could be confirmed that foot pressure and body temperature of short leg side were higher than those of short leg side. Thus, if difference exists in leg length, weight load on short leg side increases which results in higher foot pressure and body temperature, therefore enabling an assumption that mechanical problem will occur in short leg. Conclusion : When functional leg length inequality, weight bearing and pressure was getting high as a result, temperature was getting high in short leg.

유기랭킨사이클에서 핀치온도차의 변화에 따른 열교환기의 열역학적 성능특성 (Characteristics of Thermodynamic Performance of Heat Exchanger in Organic Rankine Cycle Depending on Pinch Temperature Difference)

  • 김경훈;정영관;박상희
    • 한국수소및신에너지학회논문집
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    • 제26권6호
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    • pp.590-599
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    • 2015
  • In this paper a performance analysis is carried out based on the first and second laws of thermodynamics for heat exchanger in organic Rankine cycle (ORC) for the recovery of low-temperature finite thermal energy source. In the analysis, effects of the selection of working fluid and pinch temperature difference are investigated on the performance of the heat exchanger including the effectiveness of the heat exchanger, exergy destruction, second-law efficiency, number of transfer unit (NTU), and pinch point. The temperature distribution are shown depending on the working fluids and the pinch temperature difference. The results show that the performance of the heat exchanger depends on the pinch temperature difference sensitively. As the pinch temperature increases, the exergy destruction in the evaporator increases but the effectiveness, second law efficiency and NTU decreases.

바닥 복사난방 시스템의 실내온도 제어방안에 관한 시뮬레이션 연구 (Simulation Study for Control Strategies of Indoor Air Temperature in Floor Radiant Heating System)

  • 송재엽;안병천
    • 한국지열·수열에너지학회논문집
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    • 제12권4호
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    • pp.21-26
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    • 2016
  • In this study, the control strategies of indoor air temperature in floor radiant heating system were researched by computer simulation. The temperature difference based time control method using the difference of indoor set temperature and indoor temperature is compared with the existing On-Off control one for heating control performances. As a result, the temperature difference based time control method shows better thermal environmental characteristics in case of selected operational conditions in comparison with existing control one.

Year-to-year Variability of the Vertical Temperature Structure in the Youngsan Estuary

  • Cho, Yang-Ki;Lee, Kyeong-Sig;Park, Kyung-Yang
    • Ocean and Polar Research
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    • 제31권3호
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    • pp.239-246
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    • 2009
  • Long-term observations were conducted between 1997 and 2002 to examine the variability of the vertical temperature structure in the Youngsan Estuary, southwest Korea, in summer. The observed hydrographic data revealed that the temperature minimum layer in the middle depth persisted through the entire summer of 2000 but was rarely observed in other years. The variability in the vertical structure might be affected by the air temperature during the previous winter and the density difference between the open sea and the estuary. In 2000, the air temperature in the previous winter was lowest and the horizontal density difference during summer was largest. The large horizontal density difference probably produced more active driving of warm water along the bottom, which would have intruded into the Youngsan Estuary. Furthermore, the cold previous winter would have provided a better condition for maintaining cold temperatures in the middle water layer for a longer period.