• 한국압력기기공학회 논문집
• /
• 제9권1호
• /
• pp.48-55
• /
• 2013

In this paper, W-DCAP-HTR(Web-based Design Compatibility Assessment Program for High Temperature Reactor) which will be used to check the design criteria for high temperature reactor is newly proposed. To do this, the assessment procedure of the ASME Sec.III Div.5 such as time-dependent primary stress limit, accumulated inelastic strain, and creep-fatigue damage evaluation were investigated. Furthermore, the trend of candidate materials for high temperature reactor was also reviewed. Then, all assessment procedures for high temperature reactor have been computerized to enhance the efficiency and to reduce the possibility of human error during calculating procedure by hand calculation. It can be directly conducted by adopting the actual thermal and structural analysis results. The validation of W-DCAP-HTR has been demonstrated by benchmark analysis.

• International Journal of Concrete Structures and Materials
• /
• 제19권1E호
• /
• pp.33-39
• /
• 2007

The magnitude and distribution of hydration heat of concrete structures are related to the thermal properties of each component of the concrete, the initial temperature, the type of formwork, and the ambient temperature of exposed surfaces. Even though the reinforcing steel bar has completely different thermal properties, it has been excluded in the thermal analysis of the concrete structures for uncertain reasons. In this study, finite element analysis was performed on the concrete structures reinforced with steel bars in order to investigate the effect of reinforcing steel bars on the temperature and stress distribution due to the heat of hydration. As the steel content increased, the maximum temperature and the difference in the internal-external temperature decreased by 32.5% and 10.0%, respectively. It is clearly shown that the consideration of the influence of reinforcing steel bars in the heat of hydration analysis is necessary to obtain realistic solutions for the prediction of the maximum temperature and stresses of concrete structures.

• 한국조경학회지
• /
• 제30권4호
• /
• pp.28-36
• /
• 2002

The main purpose of this study was to estimate a new regression model to explain the relationship between urban forest and air temperature in summer, 2001. This study consists of two parts: correlation coefficient analysis and regression analysis. According to correlation coefficient analysis, thermal infra-red radiations of the major land use categories found significant difference in each category. However there were no significant relationship between the data (thermal infra-red radiation and NDVI) derived from Landsat-7 ETM+ image and air temperature at Automatic Weather Stations(AWSs). After estimating various regression models for summer air temperature, the final models were chosen. The final regression models consisted of two variables such as forest m and traffic facilities area. The regression models explained over 78% of the variability in air temperatures. The regression models with variables of forest area and traffic facilities area showed that the coefficient of the first variable was even more significant than the second one. However, the negative impact of the traffic facilities area was slightly greater than the positive impact of the forest area. Consequently, the effects of forest area and traffic facilities area were apparent to explain summer air temperature in Seoul. Therefore two policies have the most important implications to mitigate the summer air temperature in Seoul: to expand and to conserve the urban forest; and to change the Oafnc facilities'characteristics. The results from this study are expected to be useful not merely in informing the public that urban forest mitigates summer air temperahne, but in urging the necessity of budgets for trees and managing urban forests. It is recommended that field swey of summer air temperature be Performed for the vadidation of the models. The main purpose of this study was to estimate a new regression model to explain the relationship between urban forest and air temperature in summer, 2001. This study consists of two parts: correlation coefficient analysis and regression analysis. According to correlation coefficient analysis, thermal infra-red radiations of the major land use categories found significant difference in each category. However there were no significant relationship between the data (thermal infra-red radiation and NDVI) derived from Landsat-7 ETM+ image and air temperature at Automatic Weather Stations(AWSs). After estimating various regression models for summer air temperature, the final models were chosen. The final regression models consisted of two variables such as forest m and traffic facilities area. The regression models explained over 78% of the variability in air temperatures. The regression models with variables of forest area and traffic facilities area showed that the coefficient of the first variable was even more significant than the second one. However, the negative impact of the traffic facilities area was slightly greater than the positive impact of the forest area. Consequently, the effects of forest area and traffic facilities area were apparent to explain summer air temperature in Seoul. Therefore two policies have the most important implications to mitigate the summer air temperature in Seoul: to expand and to conserve the urban forest; and to change the traffic facilities'characteristics. The results from this study are expected to be useful not merely in informing the public that urban forest mitigates summer air temperature, but in urging the necessity of budgets for trees and managing urban forests. It is recommended that field survey of summer air temperature be Performed for the vadidation of the models.

• 대한기계학회논문집A
• /
• 제38권2호
• /
• pp.193-203
• /
• 2014

터빈의 운전온도와 세라믹 입자크기를 고려한 경사기능재료(FGM)로 만들어진 회전하는 가스터빈 블레이드의 열전달해석 및 응력해석을 수행하였다. 경사기능성 블레이드는 벽 두께에 따라서 연속적인 재료물성 변화를 나타낸다. 이러한 경사기능재료의 특성과 온도에 따른 열전 재료물성 변화를 고려하여 블레이드의 시스템 강성을 얻기 위해 블레이드의 열전달해석을 먼저 수행하였다. 이 열전달해석으로 얻은 시스템 강성으로부터 복합 변형 변수를 사용한 회전하는 가스터빈 블레이드의 운동방정식을 유도하였다. 유도된 운동방정식은 상용 유한요소 모델과 해석결과 비교를 통해 그 정확성을 입증하였으며 회전주파수와 구배 지수에 따른 최대 응력의 변화를 조사하였다. 또한, 열전달해석을 통해 가장 낮은 블레이드 온도를 나타내는 구배 지수를 조사하였다.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2002년도 가을 학술발표회 논문집
• /
• pp.155-160
• /
• 2002

This study is performed to analyze of reinforced concrete beams under fire and to calculate remaining strength. The analysis is based on the assumption that plane section remains plane after bending due to load and non-linear temperature increases. Finite difference method is used to find temperature field in a section. The residual strength is attained considering the effect of temperature rise on the mechanical properties of concrete, self-equilibrium stress and reduced section. Further research in much needed on the material models of concrete since it governs temperature distribution and theoretical results.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2009년도 춘계 학술대회 제21권1호
• /
• pp.195-196
• /
• 2009

본 연구에서는 터널별 표준시간-온도곡선에 따른 내부온도 특성을 평가하고자 수치해석을 실시하였다. 수치해석은 Hydro Carbon, Hydro Carbon Modified, RABT 및 RWS 표준시간-온도곡선에 따랐다.

• 한국생물환경조절학회:학술대회논문집
• /
• 한국생물환경조절학회 1997년도 가을 심포지움 및 학술논문발표요지
• /
• pp.20-26
• /
• 1997

The design or analysis of beehouse inside temperature environment based on steady heat transfer theory causes much deviation and theoretically it is impossible to control the inside temperature lower than the outside temperature under the condition that the bee produces heat and no cooling equipment is installed. But in practical use of beehouse, the inside temperature is somehow lower than the outside temperature because of the heat inertia of concrete floor. (omitted)

• 한국환경성돌연변이발암원학회지
• /
• 제18권2호
• /
• pp.83-88
• /
• 1998

To detect the mutation in a given sequence, there are variety of methods developed by use of the gel electrophoresis. One of the methods, TGGE (Temperature Gradient Gel Electrophoresis), is a popular technique because it can detect mutations in DNA fragment with ease and at low cost. This study used 200 bp BamHI-digested DNA fragment containing the human $\varepsilon$-globin promoter which was mutated[$\varepsilon$ F1*(-141), GATA- I*(-163), and GATA-1* & $\varepsilon$F1]. This BamHI-digested DNA fragment was directly used to detect the mutated DNA fragment on 50% denaturant gel with temperature gradient of 45$^{\circ}C$ through $53^{\circ}C$. In agreement with the theoretical result of MELTSCAN program (Brossette and Wallet, 1994) the mobilities of mutated DNA fragments were shown to be nearly distinguished on the temperature gradient gel. In contrast to the above result the heteroduplex analysis under the temperature gradient condition was shown to detect the mutated DNA fragments through the heteroduplex formation between strands of mutated DNA and wild-type DNA.

• Journal of Mechanical Science and Technology
• /
• 제20권7호
• /
• pp.1089-1097
• /
• 2006

The market demand of display devices is drastically increasing in the information technology age. The research on OLED (Organic Light Emitting Diodes) display with the luminescence in itself is being more paid attention than LCD (Liquid Crystal display) with the light source from the back. The vapor deposition process is most essential in manufacturing OLED display. The temperature distribution of the linear cell in this process is closely related to securing the uniformity of organic materials on the substrate. This work analyzed the temperature distribution depending on the intervals between the crucible and the heating band as well as on the amount of the heat flux from the heating band. Moreover, the roles of the water jacket and the configuration of the cover within the linear cell were examined through the temperature analysis for six configurations of the linear cell. Under the above temperature analysis, the variations in the intervals and the amount of the heat flux were considered to have an effect on building the uniform temperature distribution within the crucible. It is predicted that the water jacket and the adequate configuration of the cover will prevent the blowout and clogging phenomena, respectively. The results can be used as the fundamental data for designing the optimal linear cell.

• Structural Engineering and Mechanics
• /
• 제57권3호
• /
• pp.543-567
• /
• 2016

This study attempts to address the buckling and free vibration characteristics of an isotropic cylindrical panel subjected to non-uniform temperature rise using numerical approach. Finite element analysis has been used in the present study. The approach involves three parts, in the first part non-uniform temperature field is obtained using heat transfer analysis, in the second part, the stress field is computed under the thermal load using static condition and, the last part, the buckling and pre-stressed modal analysis are carried out to compute critical buckling temperature as well as natural frequencies and associated mode shapes. In the present study, the effect of non-uniform temperature field, heat sink temperatures and in-plane boundary constraints are considered. The relation between buckling temperature under uniform and non-uniform temperature fields has been established. Results revealed that decrease (Case (ii)) type temperature variation field influences the fundamental buckling mode shape significantly. Further, it is observed that natural frequencies under free vibration state, decreases as temperature increases. However, the reduction is significantly higher for the lowest natural frequency. It is also found that, with an increase in temperature, nodal and anti-nodal positions of free vibration mode shapes is shifting towards the location where the intensity of the heat source is high and structural stiffness is low.