• 대한기계학회논문집A
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• 제27권5호
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• pp.705-712
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• 2003

Analysis for the thermal stress distribution in the laminated plates containing a hot-spot(local heating region) is performed. It is assumed that the local heating region induces only mechanical stress by the thermal expansion but effect of the thermal conduction is neglected. The region is regarded equivalent to a homogeneous inclusion expanding in a laminated medium. As an example, Au/YBCO/Al$_2$O$_3$laminate which is often employed for High Temperature Superconducting Fault Current Limiter(HTS FCL) has been analyzed. Effects of heat input, thickness of each layer and the got spot size upon the stress distribution in the hot-spot have been investigated. For a constant heat generation into the hot-spot, as the thickness of the Al$_2$O$_3$substrate increases, the stress in the YBCO layer is peculiarly oscillated, and the curvature of laminate has a maximum at a certain thickness of the Al$_2$O$_3$.

• 한국의류학회지
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• 제25권10호
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• pp.1745-1753
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• 2001

본 연구는 한랭 환경 하에서의 인체의 국소 가온 자극이 생리, 감각반응에 끼치는 영향을 검토했다. 건강한 성인여자 7명을 대상으로, 기온 $25^{\circ}C$, 습도50%의 환경 하에서 균일한 국소 가온을 부하 했을 때 피부온, 고막온, 손가락, 발가락 혈류량, 온냉감, 쾌적감의 반응에 미치는 영향을 검토한 결과는 다음과 같다. 1) 국소가온에 의해 가온 부위 피부온은 유의하게 상승하고 가온 부위에 따라 상승도에는 유의한 차가 보였다. 2) 국소가온에 의해 고막온은 머리의 가온 시에 높은 상승, 전완의 가온 시에 상승하고, 다른 가온 부위에서는 하강의 경향이 보였다. 3) 국소가온에 의해 혈류량의 변화는 3개의 군으로 분류된다. 가온과 함께 손가락 혈류량이 증가하는 군, 발가락 혈류량이 변화하는 군, 양쪽의 혈류량이 적게 변화하는 군으로 나누어진다. 이것을 각 피험자의 평균 피부온 수준 즉 체온조절 수준과 관계 있는 것으로 논할 수 있다 4)국소 가온에 의해 각 부 위 피부온으로의 파급효과는 머리, 상완의 가온 시에 크지만 대퇴, 하퇴 다리의 가온 시에는 대부분의 부위에서 영향이 보이지는 않았다. 5) 이와 같이 국소 가온에 의 한 생리, 감각반응은 가온 부위에 따라 다르고 머리, 상완의 가온 시에는 생리반응이 크고 하퇴, 다리의 가온시에는 국소의 감각변화가 컸다.

• Journal of Welding and Joining
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• 제28권5호
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• pp.80-85
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• 2010

This study focused on laser assisted machining (LAM) of silicon nitride ceramic that efficiently removes the material through machining of the softened zone by local heating. The effects of laser-assisted machining parameters were studied for cost reduction, and active application in processing of silicon nitride ceramics in this study. Laser assisted machining of silicon nitride allows effective cutting using CBN tool by local heating of the cutting part to the softening temperature of YSiAlON using by the laser beam. When silicon nitride is sufficiently preheated, the surface is oxidized and decomposed and then forms bloating, micro crack and silicate layer, thereby making the cutting process more advantageous. HIPSN and SSN specimens were used to study the machining characteristics. Higher laser power makes severer oxidation and decomposition of both materials. Therefore, HIPSN and SSN specimens were machined more effectively at higher power.

• 대기
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• 제23권1호
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• pp.13-21
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• 2013

In this study, the effects of atmospheric stability and surface temperature on the microscale local airflow are investigated in a hydrological suburban area using a computational fluid dynamics (CFD) model. The model domain includes the river and industrial complex for analyzing the effect of water system and topography on local airflow. The surface boundary condition is constructed using a geographic information system (GIS) data in order to more accurately build topography and buildings. In the control experiment, it is shown that the topography and buildings mainly determine the microscale airflow (wind speed and wind direction). The sensitivity experiments of atmospheric stability (neutral, stable, and unstable conditions) represent the slight changes in wind speed with the increase in vertical temperature gradient. The differential heating of ground and water surfaces influences on the local meteorological factors such as air temperature, heat flow, and airflow. These results consequentially suggest that the meteorological impact assessment is accompanied by the changes of background land and atmospheric conditions. It is also demonstrated that the numerical experiments with very high spatial resolution can be useful for understanding microscale local meteorology.

• The Korean Journal of Physiology and Pharmacology
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• 제19권1호
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• pp.9-14
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• 2015

We investigated the sweating response during passive heating (partial submersion up to the umbilical line in $42{\pm}0.5^{\circ}C$ water, 30 min) after summer and winter seasonal acclimatization (SA). Testing was performed in July during the summer, 2011 [summer-SA; temp, $25.6{\pm}1.8^{\circ}C;$ relative humidity (RH), $82.1{\pm}8.2%$] and in January during the winter, 2012 (winter-SA; temp, $-2.7{\pm}2.9^{\circ};$ RH, $65.0{\pm}13.1%$) in Cheonan ($126^{\circ}52^{\prime}N$, 33.38'E), Republic of Korea. All experiments were carried out in an automated climatic chamber (temp, $25.0{\pm}0.5^{\circ}C$: RH, $60.0{\pm}3.0%$). Fifteen healthy men (age, $23.4{\pm}2.5$ years; height, $175.0{\pm}5.9cm;$ weight, $65.3{\pm}6.1kg$) participated in the study. Local sweat onset time was delayed during winter-SA compared to that after summer-SA (p<0.001). Local sweat volume, whole body sweat volume, and evaporative loss volume decreased significantly after winter-SA compared to those after summer-SA (p<0.001). Changes in basal metabolic rate increased significantly after winter-SA (p<0.001), and tympanic temperature and mean body temperature were significantly lower after summer-SA (p<0.05). In conclusion, central sudomotor acitivity becomes sensitive to summer-SA and blunt to winter-SA in Rebubic of Korea. These results suggest that the body adjusts its temperature by economically controlling the sweating rate but does not lower the thermal dissipation rate through a more effective evaporation scheme after summer-SA than that after winter-SA.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.1554-1559
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• 2003

The objective of the present study is to reveal thermal characteristic of microcapsulated lauric acid slurry, which have high latent heat during phase change from solid to liquid, in circular pipe. Test were performed with microcapsulated lauric acid slurry in a heating test section with a constant heat flux boundary condition. Local Nusselt number and the effective thermal capacity were measured. As the size of microcapsulated lauric acid were increased, Local Nusselt number of microcapsulated lauric acid slurry were increased. The effective thermal capacity of microcapsulated lauric acid slurry was 0.5 times than it of water

• 설비공학논문집
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• 제16권11호
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• pp.1006-1012
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• 2004

The objective of the present study is to reveal thermal characteristic of micro-capsulated lauric acid slurry, which has high latent heat during phase change from solid to liquid, in circular pipe. Tests were performed with the microcapsulated lauric acid slurry in the heating test section with a constant heat flux boundary condition. Local Nusselt number and the effective thermal capacity were measured. As the sizes of microcapsulated lauric acids were increased, local Nusselt numbers of microcapsulated lauric acid slurries were increased. The effective thermal capacity of microcapsulated lauric acid slurry was 1.43 times larger than that of water.

• 한국농공학회논문집
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• 제65권3호
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• pp.1-13
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• 2023

Local governments play a critical role in achieving carbon neutrality and reducing national carbon emissions. To manage carbon emissions effectively, it is essential for local governments to analyze regional carbon emissions. In this study, we developed a model for estimating carbon emissions based on land use and analyzed regional characteristics of carbon emissions to suggest policies for achieving carbon neutrality at the regional level. Our model for calculating carbon emissions is based on an analysis of the activities that contribute to carbon emissions for each land use, and we established the spatial scope of carbon emission calculation. We applied this model to the cities and counties in Gyeongsangnam province, calculating carbon emissions from settlement and agricultural production activities and comparing regional characteristics of carbon emissions. Our analysis showed that areas with larger populations generally produced higher emissions in all categories, but we observed different results in terms of unit emissions, emissions divided by area, population, and household. Based on these findings, we propose policies such as increasing the generation of new and renewable energy using public institutions, promoting the conversion to cleaner cooking and heating energy sources, and encouraging the adoption of eco-friendly automobiles on roads. We believe that our analysis of the spatial and regional characteristics of carbon emissions can help local governments establish effective policies for reducing carbon emissions in their regions.

• 한국의류학회지
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• 제22권8호
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• pp.1020-1031
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• 1998

This study was done to investigate thermal reponses and to obtain the basic information of thermal comfort by sex and posture under the Ondol heating system. Six healthy males and females were exposed to Ondol(Room Temp.: 25$\pm$1$^{\circ}C$, 50$\pm$10%R.H, Floor Temp.:30$\pm$1$^{\circ}C$) on the of posture such as sitting, lying aside and supine on the floor for 30 minutes after 30 minutes' control phase. During the experiment, rectal temperature, skin temperature of 10 areas, local sweating rate, clothing microclimate, subjective sensation were measured. Rectal temperature gradually decreased and mean skin temperature grad-ually increased both male and female in any posture. There was not significant difference between male and female in rectal temperature and mean skin temperature. There were significant difference among the postures in rectal temperature(p<0.001) and mean skin temperature(p<0.001). In lying aside and supine on the floor, appearances of change and changes in rectal temperature and mean skin temperature were large, changes of weight were small. In sitting on the floor, appearances of change and changes in rectal temperature and mean skin temperature were small, changes of weight were large. The trunk skin tem-perature was higher in female than in male, but the extremity skin temperature was higher in male than in female. In sitting on the floor, foot skin temperature(p<0.001) was higher than any other local skin temperature. In supine on the floor, back skin temperature(p<0.001) was higher than any other local skin temperature.

• 한국의류학회지
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• 제15권2호
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• pp.127-138
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• 1991

The aim of the present stud)r has been to obtain new and additional data allolwing a better design of sports garments as well as a better choice among some materiales, through measure-ment of body surface changes in the upper trunk in movement, measurement on the effects of local heating on other parts of the body and measurement of the thermal resistance of 6 types of materials applied on a manikin. In the first experiment, the upper trunk was divided in 32 Parts, the surface of which was measured by the tape method for two upper limb positions: extension at $90^{\circ}$ and $180^{\circ}$. In the second experiment, skin temperature, local thermal sensations and whole body thermal sensation were measured every 5 minutes during 40 minutes. The four areas of the shoulder, abdomen, hande and feet were heated with the hot pack at $50^{\circ}C$. In the third experiment, the regional thermal resistance of the various materials selected, in two different cases of clothing ease, have been measured by using a thermal manikin. Resultes of experiments were: 1. Extensions cause the upper front part of the trunk surface to lengthen vertically while the back tends to stretch in width. 2. Skin temperatures of the upper limbs are influenced by the abdomen and shoulder boatings. The correlation between the whole body thermal sensation and the upper trunk thermal sensation is significantly asserted. 3. Ceramic and aluminium coated materiales offer the most effective thermal resistance; ease in clothing increases the thermal resistance at the breast and the abdomen as well as the clo value of the materials.