• Title/Summary/Keyword: thermal responses

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Dopaminergic Inhibition of Dorsal Horn Cell Activity in the Cat

  • Kim, Kyung-Chul;Shin, Hong-Kee;Kim, Kee-Soon
    • The Korean Journal of Physiology and Pharmacology
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    • v.2 no.6
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    • pp.661-670
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    • 1998
  • Dopamine has been generally known to exert antinociceptive action in behavioral pain test, such as tail flick and hot plate test, but there appears to be a great variance in the reports on the antinociceptive effect of dopamine depending on the dosage and route of drug administration and type of animal preparation. In the present study, the effects of dopamine on the responses of wide dynamic range (WDR) cells to mechanical, thermal and graded electrical stimuli were investigated, and the dopamine-induced changes in WDR cell responses were compared between animals with an intact spinal cord and the spinal animals. Spinal application of dopamine (1.3 & 2.6 mM) produced a dose-dependent inhibiton of WDR cell responses to afferent inputs, the pinch-induced or the C-fiber evoked responses being more strongly depressed than the brush-induced or the A-fiber evoked responses. The dopamine-induced inhibition was more pronounced in the spinal cat than in the cat with intact spinal cord. The responses of WDR cell to thermal stimulation were also strongly inhibited. Dopamine $D_2$ receptor antagonist, sulpiride, but not $D_1$ receptor antagonist, significantly blocked the inhibitory action of dopamine on the C-fiber and thermal responses of dorsal horn cells. These findings suggest that dopamine strongly suppresses the responses of WDR cells to afferent signals mainly through spinal dopamine $D_2$ receptors and that spinal dopaminergic processes are under the tonic inhibitory action of the descending supraspinal pathways.

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The Study on Indoor Thermal Environment during Convection Heating - Thermal Comfort by Indoor Air Temperature and Velocity - (대류난방시 실내열환경에 관한 연구 - 온도 및 기류속도에 대한 온열쾌적감-)

  • Kim Dong-Gyu;Chung Yong-Hyun
    • Journal of Environmental Science International
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    • v.14 no.2
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    • pp.209-214
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    • 2005
  • Draft is defined as an unwanted local cooling of the human body caused by air movement. It is a serious problem in many ventilated or air conditioned buildings. Often draft complaints occur although measured velocities in the occupied zone maybe lower than prescribed in existing standards. Purpose of this study is to clarify the evaluation of thermal comfort based on temperature and air velocity in winter. Experiments were performed in an environmental chamber in winter. Indoor temperature and air velocity was artificially controlled. The experiments were performed to evaluate temperature conditions and air velocity conditions by physiological and psychological responses of human. According to physiological responses and psychological responses, it was clear that the optimum air velocity is about 0.15 m/s and 0.30 m/s.

Thermal Environment of Small-size Apartments Facing in Two Different Directions (소형아파트의 방위에 따른 실내온열환경 실태와 평가)

  • 최윤정
    • Journal of the Korean Home Economics Association
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    • v.31 no.3
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    • pp.213-222
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    • 1993
  • The purpose of this study was to investigate the present conditions of thermal environment in small-size apartments. The research methods used were measuring of environmental elements and personal self-administration for the residents' thermal comfort responses. The house subjected were 25 peung apartments facing southeast and southwest directions. The results of this study were summarized as follow ; The indoor temperature and humidity of houses subjected were 25.0∼27.3℃, 37.1∼42.5%. Compared with the distribution of indoor temperature and globe temperature of houses subjected, those of southeast house were more stable. And in the residents' thermal sensation responses, the residents of southeast houses checked more often neutral zone. Therefore the thermal environment of southeast houses were more comfortable condition than southwest houses.

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Comparison of Somatostatin and Morphine Action on the Responses of Wide Dynamic Range Cells in the Dorsal Horn to Peripheral Noxious Mechanical and Heat Stimulation in Cats

  • Jung, Sung-Jun;Choi, Young-In;Kim, Jun
    • The Korean Journal of Physiology and Pharmacology
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    • v.2 no.2
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    • pp.155-163
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    • 1998
  • The purpose of present study was to compare the effects of somatostatin (SOM) and morphine (Mor) on the responses of wide dynamic range (WDR) cells to peripheral noxious stimulation. Single neuronal activity was recorded with a carbon-filament electrode at the lumbosacral enlargement of cat spinal cord. After identifying WDR cells, their responses to peripheral noxious mechanical or thermal stimuli were characterized and the effects of SOM and Mor, applied either iontophoretically or intrathecally, were studied. In most cells SOM and Mor suppressed noxious stimulus-evoked WDR neuronal activity, though a few WDR neurons showed no change or were excited by SOM and Mor. Systemically applied naloxone, a non-specific opioid antagonist, always reversed the Mor induced suppression of neuronal activity evoked by noxious mechanical stimuli, but did not always reverse the suppression of neuronal activity elicited by SOM. The suppressive effect of Mor on thermal stimulus-evoked neuronal activity was partially reversed by naloxone, while that of SOM were not reversed at all. The above results suggest that both Mor and SOM exert an inhibitory effect on thermal and mechanical stimulus-evoked WDR neuronal activity in cat spinal dorsal horn, but the mechanisms are dependent upon the functional populations of dorsal horn nociceptive neurons.

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A Study of Physiology Signal Change by Air Conditioner Temperature Change (에어컨 온도변동에 따른 생리신호 변화에 관한 연구)

  • Kum, Jong-Soo;Kim, Dong-Gyu;Kim, Hyung-Chul
    • Journal of Fisheries and Marine Sciences Education
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    • v.19 no.3
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    • pp.502-509
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    • 2007
  • This study evaluates thermal comfort by air conditioner temperature raising at the point of time that human body begins to adapt. Thermal comfort according to change of time enters by uncomfortable area gradually at general cold room temperature that magnetic pole is in human body. However, can know that keep continuous thermal comfort in case raise temperature in human body adaptation visual point. Experiments were performed in environmental chamber. Subjects were selected 4 men and 4 women whose life cycle were proved that are similar. The subjects stay in the pretesting room during the 30 minutes and enter the testing room under each experiment conditions. During the experiment, brain wave, electrocardiogram, blood pressure and thermal comfort and sensation responses were measured. In this study, physiological and psychological responses correspond under temperature raising at human body adaptation.

C0-type Reddy's theory for composite beams using FEM under thermal loads

  • Fan, Xiaoyan;Wu, Zhen
    • Structural Engineering and Mechanics
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    • v.57 no.3
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    • pp.457-471
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    • 2016
  • To analyze laminated composite and sandwich beams under temperature loads, a $C^0$-type Reddy's beam theory considering transverse normal strain is proposed in this paper. Although transverse normal strain is taken into account, the number of unknowns is not increased. Moreover, the first derivatives of transverse displacement have been taken out from the in-plane displacement fields, so that the $C^0$ interpolation functions are only required for the finite element implementation. Based on the proposed model, a three-node beam element is presented for analysis of thermal responses. Numerical results show that the proposed model can accurately and efficiently analyze the thermoelastic problems of laminated composites.

Effect of Feet Cooling and Feet Warming on the Behavioral Temperature Regulation (족부의 냉각과 가온이 행동성 체온조절에 미치는 영향)

  • Jeong, Woon-Seon
    • The Korean Journal of Community Living Science
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    • v.18 no.4
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    • pp.681-686
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    • 2007
  • This study was conducted to investigate the effects of the thermally different states of human feet on temperature regulation in winter season. Five healthy female students of age 20 volunteered as subjects to participate in the study. Physiological responses such as rectal temperature and skin temperatures as well as subjective responses of thermal comfort and thermal sensation were observed. Preferred clothing and preferred temperature were also evaluated in terms of behavioral temperature regulation. The results obtained through the experiment were statistically analyzed using paired t test. Rectal temperature was decreased greater (p<.01) and mean skin temperature was maintained higher (p<.01) in feet wanning than in feet cooling. Results of preferred clothing were coincident with those of general thermal sensation. There was a higher tendency to prefer temperature in feet wanning than feet cooling in the morning. It was concluded that keeping feet skin temperature lower in the early morning and higher in the late evening would be effective in terms of regulating circadian rhythm of core temperature.

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Seasonal Comparison in Thermal Comfort of the Human Body (인체 열쾌적성의 계절 비교)

  • Jeong, Woon-Seon
    • The Korean Journal of Community Living Science
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    • v.21 no.4
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    • pp.633-639
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    • 2010
  • This study was carried out to compare human thermoregulatory responses and preferred air temperature by feet immersion between summer and winter in terms of thermal comfort. Five healthy female university students participated in the study as subjects. They experienced feet immersion at $40^{\circ}C$ of water in the climatic chamber of $24^{\circ}C$, 50%RH from 19:30 to 21:00 in the summer and winter, respectively. Rectal temperature gradually decreased and maintained $0.08^{\circ}C$ lower in winter than summer, while mean skin temperature changed $0.4^{\circ}C$ greater in winter than summer(p=0.00). Air temperature selected by each subject for their thermal comfort revealed $0.8^{\circ}C$ higher in summer than winter(p=0.06). The results obtained suggest an increase in human thermoregulation and be used as preliminary data to maintain optimal indoor temperature in summer and winter.