• 제목/요약/키워드: Thermal responses

검색결과 428건 처리시간 0.027초

$25^{\circ}C$환경에서 $18^{\circ}C$환경으로 노출시 보온력이 상이한 의복의 착용이 체온조절 반응에 미치는 영향 (Influences of Wearing Different Thermal Insulated Clothings on Thermoregulatory Responses from $25^{\circ}C$ Environment to 18$^{\circ}C$ Environment)

  • 이종민
    • 한국의류학회지
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    • 제22권7호
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    • pp.826-832
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    • 1998
  • In order to understand the influences of wearing clothings with different thermal insula-tions when men were exposed from $25^{\circ}C$ environment to 18$^{\circ}C$ environment, thermoregulatory responses were measured on 4 healthy female college students. Subjects rested wearing T-shirts, trousers, and socks called LC(total weight 541g) at 25$\pm$1$^{\circ}C$, 50$\pm$5% R.H. and then exposed to the room conditioned in 18$\pm$1$^{\circ}C$, 50$\pm$5$^{\circ}C$ R.H. with LC as it was(LC Type) or with T-shirts, trousers, socks, training wear upper garment, the training wear lower garment called HC (total weight 1368g)(HC Type) for 120 min. The results can be summarized as follows: 1) When subjects were exposed from $25^{\circ}C$ environment to 18$^{\circ}C$ environment, decrease of rectal temperature was significantly smaller in LC Type than in HC Type. 2)Increase of heat production and weight loss had no significant difference between two types of clothing. 3)Internal thermal conductance was higher in HC Type and external thermal conductance was higher in LC Type. Therefore total thermal conductance was higher in LC Type than in HC Type. 4)Decrease of skin temperature was greater in LC Type than in HC Type. 5)Subjects felt colder with LC Type than with HC Type, but did not feel differently in comfort sensation between two types of clothing. It was suggested that less decrease of rectal temperature in LC type inspite of more dry heat loss from body might be ascribed to a shift of blood from the shell area to the core area originating in the vasoconstriction and the lowered internal thermal conductance. In conclu-sion, the importance of the state of internal heat distribution in the homeostasis seemed to be reaffirmed.

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정지궤도위성의 해양관측센서 임무 궤도 열해석 (ON-ORBIT THERMAL ANALYSIS FOR THE GEOSTATIONARY OCEAN COLOR IMAGER OF A GEOSTATIONARY SATELLITE)

  • 김정훈;전형열
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2009년 춘계학술대회논문집
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    • pp.135-141
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    • 2009
  • A preliminary thermal analysis is performed for the optical payload system of a geostationary satellite. The optical payload considered in this paper is GOCI(Geostationary Ocean Color Imager) of COMS of Korea. The radiative and conductive thermal models are employed in order to predict thermal responses of the GOCI on the geostationary orbit. According to the results of this analysis are as follows: 1) the GOCI instrument thermal control is satisfactory to provide the temperatures for the GOCI performances, 2) the thermal control is defined and interfaces are validated, and 3) the entrance baffle temperature is found slightly out its specification, therefore further detailed analyses should be continued on this element.

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통신해양기상위성 해양탑재체 정지궤도 예비 열해석 (PRELIMINARY ON-ORBIT THERMAL ANALYSIS FOR THE GEOSTATIONARY OCEAN COLOR IMAGER OF COMS)

  • 김정훈;전형열;한조영
    • 한국전산유체공학회지
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    • 제15권1호
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    • pp.24-30
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    • 2010
  • A preliminary thermal analysis is performed for the optical payload system of a geostationary satellite. The optical payload considered in this paper is GOCI(Geostationary Ocean Color Imager) of COMS of Korea. The radiative and conductive thermal models are employed in order to predict thermal responses of the GOCI on the geostationary orbit. The results of this analysis are as follows: 1) the GOCI instrument thermal control is satisfactory to provide the temperatures for the GOCI performances, 2) the thermal control is defined and interfaces are validated, and 3) the entrance baffle temperature and shutter wheel motor gradient are found slightly out their specification, therefore further detailed analyses should be continued on these elements.

인공위성 패널 열해석모델 간소화 알고리즘 연구 (A STUDY ON THERMAL MODEL REDUCTION ALGORITHM FOR SATELLITE PANEL)

  • 김정훈;전형열;김승조
    • 한국전산유체공학회지
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    • 제17권4호
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    • pp.9-15
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    • 2012
  • Thermal model reduction algorithms and techniques are introduced to condense a huge satellite panel thermal model into the simplified model on the purpose of calculating the thermal responses of a satellite on orbit. Guyan condensation algorithm with the substitution matrix manipulation is developed and the mathematical procedure is depicted step by step. A block-form LU decomposition method is also invited to compare the developed algorithm. The constructed reduced thermal model induced from the detailed model based on a real satellite panel is satisfying the correlation criterion of ${\pm}2^{\circ}C$ for the validity accuracy. Guyan condensation algorithm is superior to the block-form LU decomposition method on computation time.

전통온돌방의 실내온열환경 및 온열감에 관한 연구 (Evaluation of Indoor Thermal Environment and Thermal Sensation in Traditional Ondol Room)

  • 김난행;손장열
    • 한국주거학회논문집
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    • 제15권2호
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    • pp.19-25
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    • 2004
  • The aim of the research was to evaluate the characteristics of indoor thermal environment and thermal sensation in the traditional Ondol room. Indoor thermal factors including air temperature, operative temperature, floor surface temperature, relative humidity, PMV, OT were measured, and survey was carried out to understand subjective responses of resident's related to indoor thermal environment in Ondol room. The analysed houses are: the Chung hyo dang(the head house of Ryu family in Andong) and the Pyeung won jung(the traditional house in Yesan). The purpose of the survey was to know the relationship between resident's sensation and thermal environmental indicators such as air temperature, relative humidity, floor surface temperature, OT. The experimental results have pointed out how Ondol room may lead to comfortable and uniform indoor thermal environments.

Thermal post-buckling analysis of porous functionally graded pipes with initial geometric imperfection

  • Xu, Jia-Qin;She, Gui-Lin
    • Geomechanics and Engineering
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    • 제31권3호
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    • pp.329-337
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    • 2022
  • In this paper, the thermal post-buckling characteristics of functionally graded (FG) pipes with initial geometric imperfection are studied. Considering the influence of initial geometric defects, temperature and geometric nonlinearity, Euler-Lagrange principle is used to derive the nonlinear governing equations of the FG pipes. Considering three different boundary conditions, the two-step perturbation method is used to solve the nonlinear governing equations, and the expressions of thermal post-buckling responses are also obtained. Finally, the correctness of this paper is verified by numerical analyses, and the effects of initial geometric defects, functional graded index, elastic foundation, porosity, thickness of pipe and boundary conditions on thermal post-buckling response are analyzed. It is found that, bifurcation buckling exists for the pipes without initial geometric imperfection. In contrast, there is no bifurcation buckling phenomenon for the pipes with initial geometric imperfection. Meanwhile, the elastic stiffness can significantly improve thermal post-buckling load and thermal post-buckling strength. The larger the porosity, the greater the thermal buckling load and the thermal buckling strength.

흰쥐의 척수에서 Glutamate가 매개하는 Nociceptive Response에 있어서 Protein kinase C의 관련성 (The Involvement of Protein kinase C in Glutamate-Mediated Nociceptive Response at the Spinal Cord of Rats)

  • 김성정;박전희;이영욱;양성준;이종은;이병천;손의동;허인회
    • 약학회지
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    • 제43권2호
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    • pp.263-273
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    • 1999
  • When glutamate was infected intrathecally, the result is similar to those produced by TPA injected. The involvement of protein kinase C (PKC) in the nociceptive responses in rat dorsal horn neurons of lumbar spinal cord was studied. In test with formalin, a PKC inhibitor (chelerythrine) inhibited dose-dependently the formalin-induced behavior response. Neomycin also inhibited it significantly. But, a PKC activator (12-O-tetradecanoylphorbol-13-ester, TPA) showed reverse effect. When gluatamate was injected intrathecally, we observed the result is smilar to those produced by TPA injection. On the other hand, intrathecal injection of glutamate induced thermal and mechanical hyperalgesia. In Tail-flick test, we examined the involvement of PKC on the glutamate-indeced thermal hyperalgesia. Chelerythrine showed an inhibitory effect and TPA enhanced thermal response. Glutamate decreased the mechanical threshold significantly. A pretreatment of chelerythrine and neomycin inhibited glutamate-induced mechanical hyperalgesia, but the effect of neomycin was not significant. TPA had little effect on the mechanical nociceptive response. These results suggest that the PKC activation through metabotropic receptor at postsynaptic region of spinal cord dorsal horn neurons may influence on the persistent nociception produced by chemical stimulation with formalin, thermal and mechanical hyperalgesia induced by glutamate.

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Multiple crack evaluation on concrete using a line laser thermography scanning system

  • Jang, Keunyoung;An, Yun-Kyu
    • Smart Structures and Systems
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    • 제22권2호
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    • pp.201-207
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    • 2018
  • This paper proposes a line laser thermography scanning (LLTS) system for multiple crack evaluation on a concrete structure, as the core technology for unmanned aerial vehicle-mounted crack inspection. The LLTS system consists of a line shape continuous-wave laser source, an infrared (IR) camera, a control computer and a scanning jig. The line laser generates thermal waves on a target concrete structure, and the IR camera simultaneously measures the corresponding thermal responses. By spatially scanning the LLTS system along a target concrete structure, multiple cracks even in a large scale concrete structure can be effectively visualized and evaluated. Since raw IR data obtained by scanning the LLTS system, however, includes timely- and spatially-varying IR images due to the limited field of view (FOV) of the LLTS system, a novel time-spatial-integrated (TSI) coordinate transform algorithm is developed for precise crack evaluation in a static condition. The proposed system has the following technical advantages: (1) the thermal wave propagation is effectively induced on a concrete structure with low thermal conductivity of approximately 0.8 W/m K; (2) the limited FOV issues can be solved by the TSI coordinate transform; and (3) multiple cracks are able to be visualized and evaluated by normalizing the responses based on phase mapping and spatial derivative processes. The proposed LLTS system is experimentally validated using a concrete specimen with various cracks. The experimental results reveal that the LLTS system successfully visualizes and evaluates multiple cracks without false alarms.

비타민 E 소재의 인체생리반응 및 쾌적성 평가 (Evaluation of Thermal Physiological Responses and Comfort in Vitamin E Fabric)

  • 임순;정명희
    • 복식문화연구
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    • 제13권3호
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    • pp.406-413
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    • 2005
  • This study performed the evaluation of skin temperature, heart rate, temperature and relative humidity of microclimate, and subjective sensation, such as thermal sensation, wet sensation and comfort sensation to estimate physiological responses of the human body and its comfortable feeling to the vitamin E fabric. Experiments were performed on the five healthy adult women whose average age was 21, at climate chamber in which temperature, relative humidity and air current were set up below $30{\pm}\;1^{\circ}C$, $50{\pm}\;15\%$ and 0.2m/s, respectively. Two kinds of clothes were used for experiments: unfinished sports clothes, with the same form and the same size, of short-sleeved knit shirt and long trousers made with $100\%$ cotton, and finished sports clothes printed with the vitamin E solution of the level of $0.88\%$. Exercises of walking (about 105 steps/minute) with the exercise intensity of 2.5 were performed for 20 minutes using treadmill. In result, the study showed significant difference (p<0.01) in average skin temperature between unfinished and finished sport clothes, and represented higher value with having unfinished sport clothes in wear than with finished one. The study also showed significant difference (p<0.01) in heart rate only during the period of exercise, and represented higher value generally with unfinished sport clothes than with finished one. There were significant differences not only in temperature of microclimate (p<0.01) but also in humidity of microclimate (p<0.05) between two sport clothes. As for the evaluation of subjective sensation, the study showed significant difference (p<0.05) in thermal sensation between the two kinds of sport clothes, significant difference in wet sensation only during the period of exercise, and significant difference (p<0.05) in comfort sensation only during the period of recovery.

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