• 제목/요약/키워드: heat index

검색결과 857건 처리시간 0.026초

환경보건적 요소가 도시 내 폭염 취약성 평가 결과에 미치는 영향 분석 (The Impact of Environmental Health Factors on Extreme-heat Vulnerability Assessment in a Metropolitan City)

  • 이원정;강재은;김유근
    • 한국환경보건학회지
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    • 제39권6호
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    • pp.492-504
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    • 2013
  • Objectives: This analysis seeks to evaluate the impact of environmental health factors (EHF; e.g. hospital beds per capita, employees of medical institutions) on extreme-heat vulnerability assessment in Busan Metropolitan City during 2006-2010. Methods: According to the vulnerability concept suggested by the Intergovernmental Panel on Climate Change (IPCC), extreme-heat vulnerability is comprised of the categories of Exposure, Sensitivity, and Adaptive Capacity (including EHF). The indexes of the Exposure and Sensitivity categories indicate positive effects, while the Adaptive capacity index indicates a negative effect on extreme-heat vulnerability. Variables of each category were standardized by the re-scaling method, and then each regional relative vulnerability was computed with the vulnerability index calculation formula. Results: The extreme-heat vulnerability index (EVI) excepting EHF was much higher in urban areas than in suburban areas within the metropolitan area. When EHF was considered, the difference in the EVI between the two areas was reduced due to the increase of the Adaptive capacity index in urban areas. The low EVI in suburban areas was induced by a dominant effect of natural environmental factors (e.g. green area) within the Adaptive capacity category. Conclusions: To reduce the vulnerability to extreme heat in urban areas, which were more frequently exposed to extreme heat than others areas, public health and natural environments need to be improved in sensitive areas.

붕소/실리콘 졸로 도포된 목재의 열위험성 평가 (Heat Risk Assessment of Wood Coated with Boron/Silicone Sol)

  • 진의;정영진
    • 한국화재소방학회논문지
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    • 제33권3호
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    • pp.9-20
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    • 2019
  • 본 연구는 붕소/실리콘 화합물을 건축 내장재용 목재에 도포한 후 화재위험성을 열 위험성에대하여 화재성능지수와 화재성장지수를 중심으로 조사하였다. 화합물은 Boric acid와 Boronic acid 유도체를 Tetraethoxyorthosilicate와 반응시켜 합성하였다. 열방출 성질은 Cone calorimeter (ISO 5660-1)를 사용하여 측정하였으며 편백나무를 사용하였다. 화재강도는 외부 열 유속(External heat flux)을 50 kW/㎡로 고정시켰다. 연소시킨 후 측정된 화재성능지수는 편백나무와 비교하여 Boric acid/silicone (BA/Si) sol이 1.6배, Isobutylboronic Acid/silicone 졸 (IBBA/Si)과 Phenyl boronic acid/silicone 졸 (PBA/Si)은 각각 1.1배 증가하였다. 화재성능지수에 의한 화재위험성은 BA/Si < IBBA/Si ≈ PBA/Si 순으로 증가하였다. 화재성장지수는 편백나무와 비교하여 BA/Si와 IBBA/Si는 각각 94%, 8% 감소하였고 PBA/Si는 17% 증가하였다. 화재성장지수에 의한 화재위험성은 BA/Si < IBBA/Si < PBA/Si 순으로 증가하였다. 화재위험성을 종합적으로 평가하면 BA/Si < IBBA/Si < PBA/Si 순으로 높았다.

2018년 폭염 기간 동안 경북의 내륙과 해안 도시 간 열 환경 비교 - 대구와 포항의 비교 - (Comparison of Thermal Environment between Inland and Coastal Cities in Gyeongbuk during the Heat Wave of 2018 - Comparison between Daegu and Pohang -)

  • 추승현;안은지;김해동
    • 한국환경과학회지
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    • 제30권8호
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    • pp.621-628
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    • 2021
  • The characteristics of time changes in air temperature, DI (discomfort index) and WBGT (wet-bulb globe temperature) were investigated for inland city (daegu) and coastal city (pohang) of Gyeongbuk Province during the 2018 consecutive heat wave season. The time when the temperature dropped below 33℃ was around 19h in both regions. As such, the two regions were similar with respect to the time up to which the heatwave warning levels continued. However, the discomfort index (DI) was higher than 27 in Pohang. Most people feel unpleasant when an discomfort index of 27 or higher appears. The results indicated that Korea's night-time thermal environment during the summers is particularly poor in the southern coastal areas. WBGT began at 09:00 and lasted until 21:00, with a score of 31 or higher; this score, in principle, corresponded with the duration of outdoor activity in both regions. Therefore, it was found that outdoor work was at a level where all day long had to be stopped in both areas during the heat wave. Although time changes in temperature and WBGT were similar in both regions, Discomfort Index (DI) differed significantly. The difference refers to the fact that Pohang is strongly affected by the high heat capacity effect and the supply of water vapor from the sea.

한반도 2007년 여름철 인지온도 특성 연구 (A Study on the Characteristics of Perceived Temperature over the Korean Peninsula During 2007 Summer)

  • 변재영;김정식;김지영;최병철;최영진
    • 대기
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    • 제18권2호
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    • pp.137-146
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    • 2008
  • This study examines one thermal index, perceived temperature (PT), over the Korean Peninsula during 2007 summer. Heat/cold stress has been described using air temperature and humidity for warm seasons and air temperature and wind velocity in the cold conditions, while PT is based on a heat budget model of the human body that considers air temperature, humidity, wind velocity and radiation effect regardless of climates, regions and seasons. PT is higher about $4-5^{\circ}C$ than air temperature in the summer. Humidity increases PT, while wind tends to reduces PT possibly by evaporation of water vapor. The geographical distribution of summer PT indicates that the lowest PT happened in the east central region, with the appearance of the highest PT in the inland of southern region in Korea. Although the latitudinal trend shows that PT decreases northward, inland PT is higher than that of coastal region. Compared to the heat index or the discomfort index that considers air temperature and humidity, PT represents distinctive regional characteristics of thermal comfort. The distribution of PT shows that it may be a useful thermal index for the assessment of thermal comfort or stress region in the Korean Peninsula.

Effects of heat stress on conception in Holstein and Jersey cattle and oocyte maturation in vitro

  • Jihwan Lee;Doosan Kim;Junkyu Son;Donghyeon Kim;Eunjeong Jeon;Dajinsol Jung;Manhye Han;Seungmin Ha;Seongsoo Hwang;Inchul Choi
    • Journal of Animal Science and Technology
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    • 제65권2호
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    • pp.324-335
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    • 2023
  • Korea, located in East Asia in the northern hemisphere, is experiencing severe climate changes. Specifically, the heat stress caused by global warming is negatively affecting the dairy sector, including milk production and reproductive performance, as the major dairy cattle Holstein-Friesian is particularly susceptible to heat stress. Here, we collected artificial insemination and pregnancy data of the Holstein and the Jersey cows from a dairy farm from 2014 to 2021 and analyzed the association between the conception rate and the temperature-humidity index, calculated using the data from the closest official weather station. As the temperature-humidity index threshold increased, the conception rate gradually decreased. However, this decrease was steeper in the Holstein breed than in the Jersey one at a temperature-humidity index threshold of 75. To evaluate the effects of heat stress on the oocyte quality, we examined the nuclear and cytoplasmic maturation of Holstein (n = 158, obtained from six animals) and Jersey oocytes (n = 123, obtained from six animals), obtained by ovum pick-up. There were no differences in the nuclear maturation between the different conditions (heat stress: 40.5℃, non- heat stress: 37.5℃) or breeds, although the Holstein oocytes seemed to have a lower metaphase II development (p = 0.0521) after in vitro maturation under heat stress conditions. However, we found that the Holstein metaphase II oocytes exposed to heat stress presented more reactive oxygen species and a peripheral distribution of the mitochondria, compared to those of the Jersey cattle. Here, we show that weather information from local meteorological stations can be used to calculate the temperature-humidity index threshold at which heat stress influences the conception rate, and that the Jersey cows are more tolerant to heat stress in terms of their conception rate at a temperature-humidity index over 75. The lower fertility of the Holstein cows is likely attributed to impaired cytoplasmic maturation induced by heat stress. Thus, the Jersey cows can be a good breed for the sustainability of dairy farms for addressing climate changes in South Korea, as they are more resistant to hyperthermia.

Impact of Vegetation in Reducing Heat Island Phenomenon of Fukuoka City By Applying Remote Sensing Technique

  • Shibata Satoshi;Gotoh Keinosuke;Tachiiri Kaoru
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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    • pp.541-544
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    • 2004
  • Recently, the heat island phenomenon in which the temperature of a city part rises from the circumference ground has developed into a big problem. In this study, we aimed at examining the impact of increasing vegetation in urban areas to reduce the heat island phenomenon by taking the Fukuoka City of Japan as a case. In order to discuss the relation between vegetation environment and the heat island phenomenon, we have calculated Normalized Difference Vegetation Index (NDVI) and mapped the spatial vegetation distribution. These are then compared with the heat island phenomenon investigations in Fukuoka City. The results of the study revealed that the areas showing comparatively lesser heat island phenomenon are those having increased vegetation.

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사상체질에 따른 한열변증의 차이에 관한 연구 (Study on the Difference of Cold-heat Patterns According to Sasang Cinstitution)

  • 박수정;이영섭;주종천
    • 사상체질의학회지
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    • 제29권4호
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    • pp.326-335
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    • 2017
  • Objectives The purpose of this study was to analyze the difference of cold-heat pattern according to sasang constitution. Methods 3891 subjects were joined in this study. The sasang cinstitution diagnosis were proceeded by sasang constitution experts. The questionnaires and anthropometric measurements of the subjects were collected. Results The effect of gender and body mass index on the cold-heat pattern according to sasang constitution were significant. The effect of age on the cold-heat pattern according to sasang constitution were not significant. The distribution of short form-12 and blood test on the cold-heat pattern according to sasang constitution were significant. Conclusions There were significant different distribution of cold-heat pattern asscording to sasang constitution by gender, body mass index, short form-12, blood test.

공동주택의 하절기 개구부 밀폐 시 지붕면 일사수열이 최상층 실내온열환경에 미치는 영향 분석 (Analysis of the Irradiated Solar Heat Effect on Indoor Thermal Environment of the ToP Floor Units of Apartment Houses in the Summer - On Condition that All Openings of the Units are Closed -)

  • 최동호
    • 한국태양에너지학회 논문집
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    • 제24권4호
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    • pp.45-53
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    • 2004
  • In the summer, the irradiated solar heat gain through the roof has an effect on the thermal environment of the top floor units of apartment houses. This paper investigated the differences of the indoor air temperature and thermal comfort index between the top floor unit and the middle floor unit by measuring them at the sample houses. The purpose of this paper is to provide quantitative data about the irradiated solar heat gain during the summertime through the roof of an apartment house and these data to be the source to reevaluate the appropriate roof insulation efficiency. From this study, we obtained the brief results as follows. Indoor air temperature at the top floor unit is $1.2\sim2.2^{\circ}C$ higher than that of middle floor unit. The evaluation of the indoor thermal comfort index at each sample rooms reveals notable thermal differences between the two units. Top floor units need more cooling load during the summertime compared to middle floor units. Therefore, solutions to reduce solar Heat gain at top floor units to be considered.

남한의 체감 무더위의 기후학 (The Climatology of Perceived Sultriness in South Korea)

  • 최광용;최종남;김종욱;손석우
    • 대한지리학회지
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    • 제37권4호
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    • pp.385-402
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    • 2002
  • 본 연구에서는 지난 26년간 (1973~1998) 기온과 상대습도에서 산출한 열지수(Heat Index)를 분석하여, 남한에서 발생한 생리기후적 체감 무더위의 시.공간적 분포 특징을 살펴보았다. 그 결과, 공간적으로, 중서부 내륙지방, 남서부 내륙지방, 남동부 내륙 지방을 중심으로 주요 생리기후 임계치 이상을 기록한 무더위가 빈번하게 발생하였다. 특히, 남동부 내륙의 밀양 지역은 타 지역에 비해 보다 빈번하게 장기간에 걸친 높은 열지수를 기록하여 남한에서 가장 무더운 생리기후적 극서지임이 밝혀졌다. 시간적으로, 1990년대에 접어들어 대부분의 연구지역에서 각 생리임계치 이상을 기록한 무더위의 발생빈도가 많이 증가하였다. 특히, 1994년은 연구기간 중 각 생리임계치 이상의 무더위 발생빈도가 남한 전 지역에 걸쳐 가장 높게 나타난 해였다. 보편적으로 일년 중 40.6$^{\circ}C$ 이상의 열지수를 나타내는 강한 무더위는 주로 여름장마가 끝나는 7월 말에서 1-2일간의 작은 강수가 시작되는 8월 초순 사이에 발생하였다. 이러한 남한의 무더위 발생의 시.공간적 분포 패턴은 대규모의 기단의 움직임뿐만 아니라 국지적인 지형, 위도, 해발고도, 수체 또는 도시화, 산업화. 조림사업 등의 자연적 인위적 기후 인자의 영향을 받아 지역마다 다양하게 나타났다.

희박 예혼합 덤프 연소기에서 OH 자발광을 이용한 열 방출에 관한 실험적 연구 (Experimental Study on Heat Release in a Lean Premixed Dump Combustor using OH Chemiluminescence Images)

  • 문건필;이종호;전충환;장영준
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 추계학술대회
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    • pp.1146-1151
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    • 2004
  • Measurements of OH chemiluminescence in an atmospheric pressure, laboratory-scale dump combustor at equivalence ratios ranging from 0.63 to 0.89 were reported. The signal from the first electronically excited state of OH to ground state was detected through a band-pass filter with an ICCD. The objectives of this study are two: One is to see the effects of equivalence ratio on global heat release rate and local Rayleigh index distribution. To get the local Rayleigh index distribution, the line-of-sight images were inverted by tomographic method, such as Abel de-convolution. Another aim is to investigate the validity of using OH chemiluminescence acquired with an ICCD as a qualitative measure of local heat release. For constant inlet velocity and temperature, the overall intensities of OH emission acquired at different equivalence ratio showed periodic and higher value at high equivalence ratio. OH intensity averaged over one period of pressure increased exponentially with equivalence ratio. Local Rayleigh index distribution clearly showed the region of amplifying or damping the combustion instability as equivalence ratio increased. It could provide an information/insights on active control such as secondary fuel injection. Finally, local heat release rate derived from reconstructed OH images were presented for typical locations.

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