• 제목/요약/키워드: Heat index

검색결과 854건 처리시간 0.028초

상변화 냉각시스템의 정량적 성능지수 연구 (A Study on Quantitative Performance Index for Phase-Change Cooling Systems)

  • 장명언;송혜은
    • 한국군사과학기술학회지
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    • 제23권3호
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    • pp.237-245
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    • 2020
  • In this paper, I introduce Phase-Change Cooling for thermal management of high power devices that can be applied to High Power Laser and Electric Propulsion Systems which are composed of multiple distributed superheat sources. Phase-Change Cooling can be good used to efficient cooling of their heat sources. Phase-Change Cooling has extremely high efficiency of two-phase heat transport by utilizing heat of vaporization, relatively low flow rates and reduced pumps power. And I suggest TPI(Thermal Performance Index) which is a quantitative performance index of Phase-Change Cooling for thermal management. I quantify the performance of Phase-Change Cooling by introducing TPI. I present the test results of TPI's changing refrigerant, heat sink and flow rate of the Phase-Change Cooling system through the experiments and analyze these results.

한열변증 설문지와 일반적 건강 검진 결과와의 상호 연관성에 관한 비교 연구 (Health Test for Searching of Correlation and the Index of the Cold-heat Patternization Comparison of the Questionnaires for the Cold-heat Patternization and the Ordinary)

  • 백태선;박영재;박영배;박재형;임재중
    • 대한한의진단학회지
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    • 제9권2호
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    • pp.145-151
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    • 2005
  • Background and purpose: The cold-heat patternization is one of the most frequently use for diagnostic method in oriental medicine. But it is still an unclear scientific mechanism and the objective index. the aim of this study is to search the objective index of the cold-heat patternization, comparing with ordinary health test. Method: The study group comprised 101 Korean, male:female ratio 51:50, with a mean age of 49.74 years. The results of the questionnaires for cold-heat patternization were compared with the western health test that it consist of height, weight, muscle mass, body fat, WBC, Hb, ALT, AST, TG, Total cholesterol, glucose, HDL-cholesterol, free-T4 and TSH, measured in the health promotion center of the hospital of Chungnam university Result: The cold patternization were significantly higher in the women than the man. The somothing of the questionmaires for the heat patternization were positive correlated with TG, TSH, glucose, Hb, free T4, weight, musle mass(p<0.05). But there were no correlation in the gross. The somothing of the questionnaires for the cold patternization were negative correlated with the weight, musle mass, body fat, glucose, Hb and ALT(p<0.05), Especially there were strong negative correlation with the weight and muscle mass(p<0,01). Conclusion: The present study shows there is no definitive index for the cold-heat patternization in the ordinary health test. But the weight and muscle mass can be useful index of the cold patternization.

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높은 체감온도가 서울의 여름철 질병 사망자 증가에 미치는 영향, 1991-2000 (The Impact of High Apparent Temperature on the Increase of Summertime Disease-related Mortality in Seoul: 1991-2000)

  • 최광용;최종남;권호장
    • Journal of Preventive Medicine and Public Health
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    • 제38권3호
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    • pp.283-290
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    • 2005
  • Objectives : The aim of this paper was to examine the relationship between the summertime (June to August) heat index, which quantifies the bioclimatic apparent temperature in sultry weather, and the daily disease-related mortality in Seoul for the period from 1991 to 2000. Methods : The daily maximum (or minimum) summertime heat indices, which show synergetic apparent temperatures, were calculated from the six hourly temperatures and real time humidity data for Seoul from 1991 to 2000. The disease-related daily mortality was extracted with respect to types of disease, age and sex, etc. and compared with the time series of the daily heat indices. Results : The summertime mortality in 1994 exceeded the normal by 626 persons. Specifically, blood circulation-related and cancer-related mortalities increased in 1994 by 29.7% (224 persons) and 15.4% (107 persons), respectively, compared with those in 1993. Elderly persons, those above 65 years, were shown to be highly susceptible to strong heat waves, whereas the other age and sex-based groups showed no significant difference in mortality. In particular, a heat wave episode on the 22nd of July 2004 ($>45^{\circ}C$ daily heat index) resulted in double the normal number of mortalities after a lag time of 3 days. Specifically, blood circulation-related mortalities, such as cerebral infraction, were predominant causes. Overall, a critical mortality threshold was reached when the heat index exceeded approximately $37^{\circ}C$, which corresponds to human body temperature. A linear regression model based on the heat indices above $37^{\circ}C$, with a 3 day lag time, accounted for 63% of the abnormally increased mortality (${\geq}+2$ standard deviations). Conclusions : This study revealed that elderly persons, those over 65 years old, are more vulnerable to mortality due to abnormal heat waves in Seoul, Korea. When the daily maximum heat index exceeds approximately $37^{\circ}C$, blood circulation-related mortality significantly increases. A linear regression model, with respect to lag-time, showed that the heat index based on a human model is a more dependable indicator for the prediction of hot weather-related mortality than the ambient air temperature.

Effects of heat stress on body temperature, milk production, and reproduction in dairy cows: a novel idea for monitoring and evaluation of heat stress - A review

  • Liu, Jiangjing;Li, Lanqi;Chen, Xiaoli;Lu, Yongqiang;Wang, Dong
    • Asian-Australasian Journal of Animal Sciences
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    • 제32권9호
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    • pp.1332-1339
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    • 2019
  • Heat stress exerts a substantial effect on dairy production. The temperature and humidity index (THI) is widely used to assess heat stress in dairy operations. Herein, we review the effects of high temperature and humidity on body temperature, feed intake, milk production, follicle development, estrous behavior, and pregnancy in dairy cows. Analyses of the effects of THI on dairy production have shown that body temperature is an important physiological parameter in the evaluation of the health state of dairy cows. Although THI is an important environmental index and can help to infer the degree of heat stress, it does not reflect the physiological changes experienced by dairy cows undergoing heat stress. However, the simultaneous measurement of THI and physiological indexes (e.g., body temperature) would be very useful for improving dairy production. The successful development of automatic detection techniques makes it possible to combine THI with other physiological indexes (i.e., body temperature and activity), which could help us to comprehensively evaluate heat stress in dairy cows and provide important technical support to effectively prevent heat stress.

폭염발생 기준 설정에 관한 연구 (A Study on Development of the Extreme Heat Standard in Korea)

  • 박종길;정우식;김은별
    • 한국환경과학회지
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    • 제17권6호
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    • pp.657-669
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    • 2008
  • Lately extreme weather event is occurring because of the global warming. Especially disaster due to the extreme heat are increasing but the definition and the standard of the extreme heat is obscure until now. So this study established the extreme heat standard by using the number of daily deaths. As a result, considering the climate of the megalopolis using daily maximum heat index and daily maximum temperature was the best for the standard of the extreme heat. And it showed that extreme heat lasted for 2 days affects the death toll the most. The regional incidence of the extreme heat is highest at August and July, September and June is following.

알레르기 비염 환자의 비내시경 평가척도와 寒熱 변증과의 상관성 (Relationship between Nasal Endoscopy Index for Pattern Identification and Cold-heat Pattern Identification in Allergic Rhinitis Patients)

  • 안진향;김민희;윤영희;최인화
    • 한방안이비인후피부과학회지
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    • 제28권4호
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    • pp.1-11
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    • 2015
  • Objective : The aim of this study was to suggest guidelines using Nasal endoscopy index for objective pattern identification in allergic rhinitis patients. we performed a clinical study to investigate the relationship between Nasal endoscopy index and Cold-heat pattern identification for allergic rhinitis patients.Methods : We assessed 32 patients with allergic rhinitis using Nasal endoscopy index and the patients filled in Cold-Heat pattern questionnaires. Then, we analyzed the relationship between Nasal endoscopy index and Cold-heat pattern identification.Results : Pale and watery rhinorrhea scores were positively correlated with Cold questionnaire score (P<0.05).Conclusion : The results suggest that pattern identification using nasal endoscopy for allergic rhinitis can be useful for assessing the diagnosis of Cold-heat pattern identification and deciding guidelines of treatment.Acknowledgments : This work was supported by a Grant of the Traditional Korean Medicine R&D Project, Ministry of Health and Welfare, Republic of Korea (HI12C1889 and HI13C0530).

반응표면법을 이용한 평행류 열교환기의 형상 최적화 (Optimal Shape of a Parallel-Flow Heat Exchanger by Using a Response Surface Method)

  • 오석진;이관수
    • 대한기계학회논문집B
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    • 제28권3호
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    • pp.296-303
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    • 2004
  • The heat and flow characteristics in a single-phase parallel-flow heat exchanger was examined numerically to obtain its optimal shape. A response surface method was introduced to approximately predict its performance with respect to the design parameters over the design domain. The inflow/outflow angle of the working fluid, the location of inlet/outlet, the protruding height of flat tube and the height of header were chosen as a design parameter The evaluation of the relative importance of the design parameters was performed based on a sensitivity analysis. An efficiency index was used as an evaluation characteristics value to simultaneously consider both the heat transfer and the pressure drop. The efficiency index of the optimum model, compared to that of the base model, was increased by 9.3%.

급성기 뇌경색 환자의 화열증상 변화와 기능회복도간의 상관관계에 대한 연구 (Correlation Study between the Changes of the Fire- and Heat- Related Symptoms and Motor Function Recovery in Acute Cerebral Infarction Patients)

  • 현상호;민경동;예영철;강아름;이은찬;문상관;조기호;정우상;박성욱;고창남
    • 대한한방내과학회지
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    • 제34권4호
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    • pp.428-437
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    • 2013
  • Objectives : The aim of this study was to examine if there is a significant correlation between the changes of Fire- and Heat- related symptoms and motor function recovery in acute cerebral infarction patients. Methods : We studied inpatients within a month after the onset of cerebral infarction who were admitted at Kyunghee University Medical Center from May 2011 to January 2013. We executed correlation analysis between Fire-heat pattern score and motricity index score at visit 1 and visit 2, and checked if there was a significant correlation between the changes of Fire-heat pattern score and changes of motricity index score. Also, we compared the changes of both scores in patients taking Fire-heat and non Fire-heat pattern prescriptions. Results : There was a significant correlation between the Fire-heat pattern score and Motricity index score at visit 1 and visit 2, and changes of Fire-heat pattern score showed significant correlation with changes of motricity index score. Patients taking Fire-heat pattern prescriptions showed significant change in Fire-heat pattern score after herb-medication treatment while patients taking non-Fire-heat prescriptions showed insignificant change in Fire-heat pattern score. Conclusions : This study provides evidence that taking a Fire-heat pattern prescription could be considered as a first line herb-medication treatment in acute cerebral infarction patients.

한열변증의 국내 임상연구 동향 분석 - 일반인의 정량지표를 중심으로 (Analysis of Clinical Research Trends on Cold-Heat Pattern Identification in Korea - Focused on Quantitative Indicators for General People)

  • 여민경;이영섭
    • 동의생리병리학회지
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    • 제31권2호
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    • pp.145-152
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    • 2017
  • The purpose of this study was to investigate the clinical research of Cold-Heat of pattern identification(PI) focused on quantitative indicators for general people in Korea, through the review of OASIS, KISS, DBpia, NDSL database. Ten clinical researches were analyzed in this study. These research gradually started from 2004 to 2009 but there was no research after 2010. Diagnosis of Cold-Heat PI all was done through a questionnaire, 7 or most researches had not used the intervention methods. Quantitative indicators related to the Cold-Heat PI mentioned in the selected 10 researches are seven, these indicators include heart rate variability(HRV), electroencephalogram, Yangdorak, respiratory index, electrogastrography, acoustic analysis index, western health test index. Related to the HRV were 3 researches, but correlation of significant indicators was a few levels(R=0.026-0.090). So far, studies regarding at the quantitative indicators of the prior the Cold-Heat PI were few, and the results of the study showed that low statistical precision, a lack of biological basis. Refer to the current state, in the future, we expect that research of quantitative indicators of scientific evidence-based through calculated and precise research concerning Cold-Heat PI be regarded as important in Korean Medicine.

온돌 온열환경지표 평가방법 (Evaluation Methods on ONDOL Thermal Environmental Index)

  • 김성조
    • 한국산업융합학회 논문집
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    • 제25권1호
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    • pp.101-110
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    • 2022
  • For this purpose, the authors proposed and proved usefulness of the modified mean skin temperature which is integrated mean radiation temperature and the effect of floor contacted heat conduction. The mean radiation temperature is applied form factor between half cross-legged human body and surrounding wall of indoor. In addition the floor contacted heat conduction is applied heat transfer coefficient of half cross-legged human body. Eight Korean young men were targeted for the experiment. From the experiment the authors excerpted physiological reaction and psychological reaction in Ondol environment which is combined physiccal environmental factor of artificial climate chamber, air and floor temperature. As a result of the experiment it is confirmed that heat conduction has more impact than heat exchange from existing research for the heat exchange between half cross-legged human body and surrounding wall in Ondol thermal environment. Thereby, it is proved the effectiveness of the modified mean skin temperature which is added floor contacted temperature to the Ondol thermal environmental evaluation index.