• Title/Summary/Keyword: cold temperature

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Effect of Cooling Hands in the Cold Water for the Physiological Responses and Clothing Comfort -Focused on Vascular Hunting Reaction, Thermal Sensation and Pain Sensation- (손의 한랭자극이 인체생리반응과 의복의 쾌적성에 미치는 영향 -한랭혈관반응, 온랭감각, 한랭통증을 중심으로-)

  • 이원자
    • The Research Journal of the Costume Culture
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    • v.12 no.2
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    • pp.279-289
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    • 2004
  • This study was conducted to compare the hunting reaction of finger in the cold water. Finger skin temperature is measured the left middle finger tip immersion in cold water of 5℃ for 30 minutes and measurements were made on finger skin temperature(Ts), thermal comfort, and cold pain sensations during the experiment at the spring (March) and Winter(December). Results were follows. Is before immersion was at the highest in spring and at the lowest in winter and was closely related to the indoor temperature Ts during immersion and recovery. Mean of finger skin temperature(MST), the skin temperature at the first rise(TTR) and amplitude of finger skin temperature reaction during immersion(AT) were significant higher in spring than that in winter(P<.01). The lowest skin temperature(LST) during the cold water immersion were significantly higher in spring than that in winter (P<.05). The frequency of the appearance of cold-Induced vase dilation(CIVD) was higher in spring than that in winter. However, time for the first temperature(TTR) and recovery time(RT) had no seasonal variation. In addition, cold pains during immersion were felt more strongly in spring than in winter. Local thermal sensation, finger thermal sensation in dynamic state during hand immersion was different from that in the Winter. Spring was slowly cold in cold water immersion.

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Relationship between the East-Asian Cold Anomalies in Winter of 2010/11 and Blocking (2010/11년 겨울의 동아시아 한랭 아노말리와 블로킹의 연관성)

  • Choi, Wookap;Kim, Young-Ah
    • Atmosphere
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    • v.26 no.1
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    • pp.193-201
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    • 2016
  • An anomalous cold-weather period occurred during January 2011 in East Asia, and this study investigates the event by focusing on the blocking phenomena formed at Northeastern Asia. The area of cold weather is determined to represent the characteristic features of abnormal cold temperature. The 2010/11 winter is divided into three periods P1, P2 (cold period), and P3. For the cold area ($30-50^{\circ}N$, $115-135^{\circ}E$) the corresponding cold period P2 is determined to be 39 days from 23 December 2010 through 30 January 2011. During P1 and P3 temperature anomalies from the climatological mean are small with large standard deviation compared to those of P2, which has large negative anomaly and small standard deviation. The period P2 is dominated by blocking, which was determined by distributions of 500-hPa geopotential height and potential temperature on the 2 PVU surface. Correlation-coefficient analyses show that during P2 the temperature in the cold area is related with pressure of Northeastern Asia, while the temperature during P1 and P3 is related with pressure of Northwest of Korea. Also, during P1 and P3 the temperature pattern shows eastward propagation, but during P2, a stationary pattern. All the observations imply that, during the cold period P2, the temperature in the cold area is related with blocking in Northeastern Asia. During P1 and P3 temperature pattern is related with 500-hPa geopotential height in Siberia, and this relationship is also observed in the climatological mean state.

Characteristics of Cooling Temperature of Cold Water Pipes Buried in the Wall of a Small Mobile Modular House (소형 이동식 모듈주택의 벽면에 냉수배관 매설에 의한 냉방온도 특성)

  • Cho, Dong-Hyun
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.21 no.3
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    • pp.110-117
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    • 2022
  • A chiller cooler absorbs the thermal energy of water to generate cold water and supplies the generated cold water to a cold water pipe buried in the wall of a small mobile modular house to greatly increase the cooling area. An attempt was made to reduce the required cooling time significantly. A small chiller cooler suitable for the cooling load of a small mobile modular house with an area less than 3.3 m2 was employed. When cooling is done during summer using a chiller cooler installed outdoors, heat absorption energy loss occurs in the cold water pipe owing to the high temperature. To address this, a study was conducted to reduce the endothermic energy loss significantly. As the mass flow rate of the cold water flowing inside the cold water pipe increased, the temperature decrease gradient of the cold water increased. From the start of the cooling operation, the air temperature of the small mobile modular house decreased linearly in proportion to the operation time. Furthermore, the temperature of the air inside the small mobile modular house decreased in proportion to the increase in the flow of water inside the cold water pipe.

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.

The Effect of Cold and Elevation on Skin Temperature (냉과 거상이 피부 온도에 미치는 영향)

  • Kim, Min-Kyu;Current, Marion E.;Kim, Hyo;Lee, Jung-Bae
    • Physical Therapy Korea
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    • v.3 no.1
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    • pp.48-56
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    • 1996
  • The research of cold therapy is preceding rarely nowadays. This study was researched to measure the skin temperature of the right foot malleolus when the leg change the situation precisely speaking it was cold, elevation, cold plus elevation. Twenty young healthy volunteers(M:10, F:10)with no history of cardiopulmonary disease, peripheral artery disease were tested. This study were analyzed by one-way-repeated ANOVA. In the first we examined the within changes of the skin temperature between before and after examination for each modality. The skin temperature at all of modalities had fallen. Therefore we could know the fact that elevation plus cold modality had fallen skin temperature significantly more than elevation or cold. And there were no significant difference between male and female. We conclude that elevation and cold therapy could be better effective on edema, contusion and sprain than cold or elevation therapy independently.

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Photochemical Response in 0-Year-Old and 1-Year-Old Needles of Picea glehnii during Cold Acclimation and Low Temperature

  • Bae, Jeong-Jin;Hara, Toshihiko;Choo, Yeon-Sik
    • Journal of Ecology and Environment
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    • v.31 no.4
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    • pp.317-325
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    • 2008
  • P. glehnii, an evergreen conifer found in northern areas, is known as a cold-resistant species. In this experiment, we measured the water content, PSⅡ efficiency, chlorophyll fluorescence, pigments of the xanthophyll-cycle and activity of enzymes of the ascorbate-glutathione cycle during cold acclimation and at subsequent low-temperature conditions to examine the importance of acclimation to cold tolerance. P. glehnii showed a decrease in PSⅡ efficiency (especially in Fv) during cold acclimation and at subsequent low temperatures. However, cold-acclimated needles showed higher PSⅡ efficiency at low temperatures than nonacclimated needles. In addition, 0-YON (first-year needles) showed an increase in $\beta$-carotene and lutein, while 1-YON (one-year-old needles) immediately developed an antioxidant mechanism in the ascorbate-gluthathione cycle as soon as they were exposed to low temperature and both 0-YON and 1-YON showed increased zeaxanthin and de-epoxidation ratios at continuous low temperature. Based on our results, we suggest that P. glehnii maintain PSⅡ efficiency at low temperature by effectively protecting the photosynthetic apparatus from photo-damage by rapid induction of an antioxidant mechanism in 1-YON and dissipation of excess energy by $\beta$-carotene and lutein in 0-YON.

Regional Characteristics of Cold Surges over the South Korea (한반도에서의 지역에 따른 상이한 한파 발생 특징)

  • Sung, Hyun-Joon;Kim, Baek-Min
    • Atmosphere
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    • v.30 no.3
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    • pp.249-256
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    • 2020
  • We investigate regional differences in the characteristics of cold surges that occurred over the South Korea during winter season (December-February, 1981/1982~2017/2018). A significant regional contrast of cold surge characteristics exists and we found that this is closely related to the spatially inhomogeneous distribution of winter-mean climatological surface temperature in association with the complex topography of the Korean peninsula. For the regions of the temperature below -1℃ (Region1; R1), the frequency of cold surges is inversely proportional to the surface temperature almost linearly. In case of the regions above -1℃ (Region2; R2), cold surge frequency does not exhibit any clear dependency on the surface temperature. Duration and number of occurrences of cold surge between the two regions showed clear difference. Dynamical evolution of cold surges before the onset showed a sharp contrast between R1 and R2. In R1, cold surface air temperature (SAT) was already predominant over East-Asia before the onset and the cold temperature was sustained after the occurrence. On the contrary, warm SAT was predominant over East-Asia before the onset in R2. The SAT suddenly drops just after the cold surge occurrence. We present different origin of wave activity and propagation characteristics between the two types: Wave-activity flux (WAF) was relatively weaker and wave disturbances moved eastward in R1 along with the WAF mainly directing eastward. In case of R2, WAF was stronger and directing southeastward in the upstream of South Korea movement erasing predominant warmer air eventually causing sudden temperature drops over southern provinces over South Korea.

Effects of Exposed Parts of Body with Garments on Human Thermoregulatory Responses to Cold Environments (추운 환경에서 노출된 부위에 따른 체온조절 반응에 대한 연구)

  • 성유진;이순원
    • Journal of the Korean Society of Clothing and Textiles
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    • v.21 no.6
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    • pp.977-987
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    • 1997
  • The present study was designed to see what the local cooling of different body regions especially head and neck, hands and feet effect physiological responses in cold environment. Four male subjects wore garments covering whole body except face and rested for 20 min and then they rested for 40 min with uncovered head, neck, hands and feet, respectively in a cold environment(10$\pm$1$^{\circ}C$, 50$\pm$5%R.H.) 1. Rectal temperature increased when hands and feet were exposed to cold environment respectively, and when head and neck, hands and feet were exposed to cold environment together. 2. Exposed skin temperatures fell in cold environment. And hands temperature was lower than any other exposed skin temperatures. The hands temperature was significantly lower when head was exposed than when head was covered. And the feet temperature were significantly lower when hands were exposed than when hands were covered. 3. Mean skin temperature was the lowest when head and neck, hands and feet were exposed simultaneously, In conclusion, skin temperatures of extremities were decreased due to exposure to the cold environment. Especially upper extremities were lower than lower extremities by exposed parts of the body. It seemed that the extremities played the role of cold receptors but head and neck didn't. And there were large heat losses from the unprotected head and neck. In cold environment of 1$0^{\circ}C$ , thus, it is suggested for the purpose of thermoregulatory responses that head and neck would be covered and extremities would be exposed, especially upper extremities.

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Comparative Transcriptome Analysis Reveals Differential Response of Phytohormone Biosynthesis Genes in Glumous Flowers of Cold-Tolerant and Cold-Sensitive Rice Varieties Upon Cold Stress at Booting Stage

  • Park, Myoung Ryoul;Kim, Ki-Young;Tyagi, Kuldeep;Baek, So-Hyeon;Yun, Song Joong
    • Korean Journal of Breeding Science
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    • v.43 no.1
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    • pp.1-13
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    • 2011
  • Low temperature stress is one of the major negative factors affecting vegetative and reproductive growth of rice. To better understand responses of rice plants to low temperature we analyzed transcriptome expression patterns in glumous flower of cold-tolerant japonica rice variety, Stejaree45, and cold-susceptible variety, HR19621-AC6 at booting stage under cold water irrigation. A total of 2,411 probes were differentially expressed by low temperature in glumous flowers of the two varieties. Some important genes involved in hormone biosynthesis showed variety-specific regulation. Expression of GA20ox3 and GA2ox, among the genes involved in GA biosynthesis, was regulated differentially in the two varieties. Among the genes involved in IAA biosynthesis, YUCCA1 and TAA1:1 showed variety-specific regulation. Among the genes involved in cytokinin biosynthsis and signaling, expression of LOG, HK1 and HK3 was significantly down-regulated only in the cold-susceptible variety. Among the genes involved in ABA biosynthesis, NSY and AAO3 were down-regulated only in the cold-tolerant variety. In general, genes involved in GA, IAA and cytokinin biosynthesis responded to cold temperature in such a way that capacity of those bioactive hormones is maintained at relatively higher levels under cold temperature in the cold-tolerant variety, which can help minimize cold stress imposed to developing reproductive organs in the cold-tolerant variety.

Experimental Study of the Effect on Cabin Thermal Comfort for Cold Storage Systems in Vehicles (축냉 시스템이 차 실내 열 쾌적성에 미치는 영향에 관한 실험적 연구)

  • Lee, Daewoong
    • Transactions of the Korean Society of Automotive Engineers
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    • v.23 no.4
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    • pp.428-435
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    • 2015
  • This paper presents the experimental study of cabin thermal comfort using a cold storage heat exchanger in a vehicle air-conditioning system. Recent vehicle-applied ISG functions for fuel economy and emission, but when vehicles stop, compressors in the air-conditioning system stop, and the cabin temperature sharply increases, making passengers feel thermal discomfort. This study conducts thermal comfort evaluation in the vehicle, which is applied to a cold storage system for the climate control wind tunnel test and the vehicle fleet road test with various airflow volume rates and ambient temperatures blowing to the cold storage heat exchanger. The experimental results, in the cold storage system, air discharge temperature is $3.1-4.2^{\circ}C$ lower than current air-conditioning system when the compressor stops and provides cold air for at least 38 extra seconds. In addition, the blowing airflow volume to the cold storage heat exchanger with various ambient temperature was examined for the control logic of the cold storage system, and in the results, the airflow volume rate is dominant over the outside temperature. For this study, a cold storage system is economically useful to keep the cabin at a thermally comfortable level during the short period when the engine stops in ISG vehicles.