• Title/Summary/Keyword: Temperature Difference

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The Comparison of Right and Left Abdominal Temperature of dysmenorrhea patients using DITI (DITI를 이용한 월경통 여성의 좌우 복부온도 비교)

  • Kim, Seung-Hyun;Ahn, Soo-Jeong;Cho, Jung-Hoon;Jang, Jun-Bock;Lee, Kyung-Sub
    • Journal of Oriental Medical Thermology
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    • v.2 no.1
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    • pp.24-28
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    • 2003
  • Purpose: We aim to research the difference of abdominal temperature in dysmenorrhea patients comparing with that of normal person. Metholds: We selected the 49 dismenorrhea patients as study group and 54 normal persons as control group, excluding the patients who have dermatitis, ared over 70 or under 10. and have extreme obesity. We compared the 4 points(Rt and Lt Gimun(LR14) and Guirae(ST29)) in thd abdomen of both group, check the temperature of those points with DITI(Dorex, DTI-16UTI) to compare the temperature difference with each other. For statistics, we use independent T-test, SPSS 8.0 for windows. Results: The temperature difference between Rt and Lt Gimun which are in upper abdomen shows statistically significant result in study group. Conclusion: The dysmenorrhea patients show larger temperature difference between Rt and Lt points in upper abdomen than normal persons. In lower abdomen, the temperature between control and study group shows little difference.

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Suggestion of New Heat Tariff Assessment for District Heating Using Exergy (엑서지를 이용한 지역난방 열요금 제도 제안)

  • Moon, Jung-Hwan;Lee, Jae-Heon;Moon, Seung-Jae;Yoo, Ho-Seon
    • Proceedings of the SAREK Conference
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    • 2008.06a
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    • pp.912-918
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    • 2008
  • In this study, the exergy which could be reflected on energetic and economic value was used to assess on heat tariff of district heating system instead of enthalpy. Exergy is difficult to apply directly to present heat charge system because of complex calculation. Therefore, the difference between supply and return temperature was converted to the exergy temperature difference for easily calculating the amount of heat. As a result of exergy analysis for a DH substation, the exergy temperature difference were not affected on surrounding temperature and pressure loss. Supply temperature, maximum difference between supply temperature and return temperature had a main effect on the exergy temperature difference. The new heat charge of a DH user was slightly reduced in winter compared with previous heat charge. Heat charges in other seasons were almost same. It is thought that heat tariff using exergy will be appropriate in terms of both DH supplier and consumer.

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The Effect of Film Thicknesses on Heat Transfer in a Rotating Heat Pipe with the Disc Evaporator (원판증발기를 가진 회전형 히트파이프에서 액막두께가 전열에 미치는 영향)

  • 권순석;장영석;유병욱
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.18 no.6
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    • pp.1572-1581
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    • 1994
  • Heat transfer characteristics in a rotating heat pipe with evaporator of the rotating disc and the condenser of the screwed groove is investigated by numerical method for various dimensionless film thicknesses, Re, C_{p}{\Delta}T/h_{fg}$, rotational speed and working fluids. The temperature difference between evaporator wall and vapor increases a little, but the temperature difference between condenser wall and vapor decreases rapidly as Re increases. As the dimensionless film thickness decreases, the temperature difference of evaporator and condenser decreases. As the rotational speed increases, the temperature difference between evaporator wall and vapor increases but the temperature difference between condenser wall and vapor decreases. The Nusselt number can be shown as a function of dimensionless film thickness and Re, that is $Nu=0.963\cdot(\delta^{-1}(\omega/\vpsilon)^{-1/2}{\cdot}Re^{0.5025})$.

Prediction of Thermal Fatigue Life of Alumina ceramics (알루미나 세라믹스의 열피로 수명 예측)

  • 정우찬;한봉석;이홍림
    • Journal of the Korean Ceramic Society
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    • v.36 no.8
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    • pp.871-875
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    • 1999
  • Theoretical equation to calculate thermal fatigue life was derived in which slow crack growth theory was adopted. The equation is function of crack growth exponent n. Cyclic thermal fatigue tests were performed at temperature difference of 175, 187 and 200$^{\circ}C$ respectively. At each temperature difference critical thermal fatigue life cycles of the alumina ceramics were 180,37 and 7 cycles. And theoretical thermal fatigue life cycles were calculated as 172, 35 and 7 cycles at the same temperature difference conditions. Therefore thermal fatigue behavior of alumina ceramics can be represented by derived equation. Also theoretical single cycle critical thermal shock temperature difference can be calculated by this equation and the result was consistent with the experimental result well.

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Temperature Reduction Effect According to Light Transmittance of Urban Street Trees - Focused on Seocho-gu in Seoul - (도시 내 가로수의 광선투과량에 따른 온도저감 효과 - 서울시 서초구를 중심으로 -)

  • Kim, Eun-Bum;Kim, Nam-Choon;Shin, Ji-Hoon;Song, Won-Kyeong;Kim, Do-Hee
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.20 no.3
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    • pp.45-54
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    • 2017
  • With rapid urbanization and reckless urban development in the 21st century, the urban environment has gradually gotten worse, and urban heat island effect has been dramatically intensified. Thus, the importance of street greenery that can mitigate the urban heat island effect has further been highlighted. In this regard, this study was aimed at selecting suitable plant species for street greenery to reduce the urban heat island effect. Towards this end, five roads located in Seocho-gu, Seoul were selected as study sites, and plant species composition and difference of surface temperature were compared and analyzed in relation to the light transmittance. The street with the greatest temperature difference is Bangbae-ro(Platanus occidentalis). On the other hand, the road with the lowest temperature difference is Nambusunhwan-doro(Metasequoia Glyptostroboides). The effect of temperature reduction was found to be associated with light transmittance.Bangbae-ro(Platanus occidentalis) with the lowest light transmittance showed the highest temperature difference and Nambusunhwan-doro(Metasequoia Glyptostroboides) with the highest light transmittance showed the lowest temperature difference. It is analyzed that there are most differences in temperature when the amount of lights coming in between the crown is small. The temperature reduction effect can be obtained by planting deciduous broad-leaved trees. Also species with dense crown and broad width of crown will be able to maximize the effect of temperature reduction. In future studies, it will be necessary to expand the other species of trees in the street, and analyze the germicidal trees and shrubs as well as the differences in the packaging materials.

Characteristic of Thermal Output of Thermally Activated Building System During the Heating Operation According to FDM Analysis (FDM 해석에 의한 구체축열시스템(TABS)의 난방운전시 방열 특성 분석)

  • Lim, Jae-Han;Song, Jin-Hee;Koo, Bo-Kyoung;Song, Seung-Yeong;Senog, Yoon-Bok
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.24 no.3
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    • pp.218-223
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    • 2012
  • This study is focused on the evaluation of thermal output of TABS (Thermally Activated Building System). The aim of this study is to evaluate TABS in terms of the temperature difference between heating medium supply temperature ($T_s$) and return temperature ($T_r$), thermal output and the surface temperature distribution according to the design flow rate and the design flow temperature. Through the transient heat transfer simulation using temperature calculation using Crank-Nicolson FDM using Physibel Voltra 6.0 W, the temperature difference between $T_s$ and ��$T_r$, thermal output and the surface temperature distribution of specific TABS was calculated and evaluated. The results show that specific thermal output and temperature difference at $60^{\circ}C$ of supply water temperature were about 162 $W/m^2$, $13.6^{\circ}C$ respectively.

Analysis of Meteorological Features and Prediction Probability Associated with the Fog Occurrence at Chuncheon (춘천의 안개발생과 관련된 기상특성분석 및 수치모의)

  • Lee Hwa Woon;Lee Kwi Ok;Baek Seung-Joo;Kim Dong Hyeok
    • Journal of Korean Society for Atmospheric Environment
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    • v.21 no.3
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    • pp.303-313
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    • 2005
  • In this study, meteorological characteristics concerning the occurrence of fog are analyzed using 4-years $(2000\~2003)$ data at Chuncheon and the probability of prediction is investigated. From the analysis of meteorological characteristics, the fog at Chuncheon occurred before sunrise time and disappeared after that time and lasted for $2\~4$ hours. When fog occurred, on the whole, wind direction was blew the northerly and wind speed was below 2.1m/s. Especially, about $42\%$ of foggy day fell on the calm $(0\~0.2\;ms^{-1})$ conditions. The difference between air temperature and dew point temperature near the surface were mainly less than $2^{\circ}C$. For the lack of water surface temperature, the water surface temperature was calculated by using Water Quality River Reservoir System (WQRRS) and then it was used as the surface boundary condition of MM5. The numerical experiment was carried out for 2 days from 1300 LST on 14 October 2003 to 1300 LST on 16 October 2003 and fog was simulated at dawn on 15 and 16 October 2003. Simulated air temperature and dew point temperature indicate the similar tendency to observation and the simulated difference between air temperature and dew point temperature has also the similar tendency within $2^{\circ}C$. Thus, the occurrence of fog is well simulated in the terms of the difference between air temperature and dew point temperature. Horizontal distribution of the difference between air temperature and dew point temperature from the numerical experiment indicates occurrence, dissipation and lasting time of fog at Chuncheon. In Chuncheon, there is close correlation between the frequency of fog day and outflow from Soyang reservoir and high frequency of occurrence due to the difference between air and cold outlet water temperature.

Influence of Seasonal Variation on Basal Metabolic Rates on Thermal Environments & Clothing Weight (생활환경온도와 착의량이 기초대사에 미치는 영향)

  • 이원자;침규남;김진선;박승순
    • The Research Journal of the Costume Culture
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    • v.8 no.3
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    • pp.374-386
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    • 2000
  • This study investigated the relation between seasonal variation of total clothing weight, room, outdoor temperature and basal metabolic rate in man. The basal metabolic rate and total clothing weight, room temperature was determined seasonal for a period of two years and grouped four seasons. Subjects (adults volunteers) who live in seoul and mokpo were compose 120 subject The results were obtained as follows. Seasonal outdoor temperature was difference of seoul and. mokpo. But room temperature in apartments was a little difference than private house. Total-clothing weight is showed seasonal variations at the seoul, private house than at the mokpo, apartment.. The basal metabolic rate is suggested there in gender difference in the basal metabolic rate (P〈.001). The basal metabolic rate increased gradually with the peak of winter sespectively and deceased again todward summer. The difference of between basal metabolic rate in summer and winter was significant room temperature, of seoul and private house, and light total clothing weight.

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The relations between Waist-to-Hip Ratio(WHR) and the abdominal temperature (복부 지방율과 하복부 온도와의 관계)

  • Choi, Eun-Mi;Cho, Jung-Hoon;Jang, Jun-Bock;Lee, Kyung-Sub
    • Journal of Oriental Medical Thermology
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    • v.2 no.1
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    • pp.56-62
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    • 2003
  • Objectives : We intented to know the relations between Waist-to-Hip Ratio(WHR) and the abdominal temperature. Methods : Among the patients who visited the oriental gynecological department in Conmaul oriental medical hospital from 2002. 10. 10 to 2002. 11. 9. 130 women were selected for this study. We measured the abdominal temperature by D.I.T.I and Waist-to-Hip Ratio(WHR) by Inbody. Results and Conclusions 1. As WHR was higher, the abdominal temperature became lower. But there was no significant difference between WHR and the abdominal temperature of the abdominal obesity group and the non-abdominal obesity group in the each state. 2. There was significant difference in the abdominal temperature related with the abdominal obesity The abdominal temperature of the non-abdominal obesity group was higer than that of abdominal obesity group. 3. There was significant difference in the WHR according to the age, but no significant difference in the abdominal temperature according to the age. 4. This study showed that the abdominal temperature became lower among the 30-39 year-old women, as WHR was higher.

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20kW Turbine Development for OTEC System (20kW OTEC 터빈 개발)

  • Han, Sangjo;Seo, JongBeom
    • The KSFM Journal of Fluid Machinery
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    • v.17 no.6
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    • pp.38-43
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    • 2014
  • In Ocean, the temperature of the deep sea water is always lower than that of the surface sea water. The temperature difference between the surface water and deep sea water is about $20^{\circ}C$. Based on thermodynamics, this temperature difference can be converted into mechanical power. The mechanical power can be converted to electricity through a generator. However, the temperature difference is relatively small compared with that of traditional steam turbines. It is difficult to apply the steam turbine technology for this small temperature difference directly. Therefore, the turbine for OTEC system using low temperature difference should be designed to meet the system requirement. The present study focuses on the development of the turbine for 20 kW OTEC system using R32. The paper includes the determination of working fluids, meridional design, turbine layout and 3D CFD results. With off-design points analysis, the full performance of 20kW OTEC turbine is investigated. Through the research, one stage radial type turbine with R32 as working fluid is successfully developed and can be applied to other high temperature heat source.