• Journal of the Korean earth science society
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• v.31 no.7
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• pp.762-771
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• 2010

The purpose of this study was to make a suggestion for the direction of writing textbook by comparing and analyzing the contents about 'Adiabatic Change' in earth science I textbooks. For this study, six textbooks were chosen among the eight government-authorized earth science I textbooks that were in general use in schools. Based on the researcher's preview of the six chosen textbooks, three categories were established as a criteria for analysis of the contents of 'adiabatic change': definitions, illustrations, and experiments. Thirty five preservice secondary teachers participated in analyzing the six textbooks based on the above three categories. Each of the six books was given an alphabet from A to F. The analysis results were as follows: Textbook A was turned out as the best textbook in the category of definition, textbook C as the best in the category of illustration, and textbook B as the best in the category of experiment about the concept of 'adiabatic change'. However, each of the six earth science textbooks showed an insufficient part in one way or the other. The results imply that the inaccurate and inappropriate information would not only make the students difficult to understand the adiabatic change but also lead them to some level of misconceptions. Therefore, there need to reconstruct the contents of textbooks to be more systematic, accurate, and complete.

• Journal of Korea Foresty Energy
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• v.21 no.2
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• pp.62-68
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• 2002

Adiabatic property of plywood wall panel was examined to evaluate their thermal conductivities. The amount of heat loss was investigated through overall heat transmission experiment. Styroform and grass wool showed less heat loss. However, yellowsoil board and laminated lumber showed high volume specific heat capacity. When the changes of indoor and outdoor temperature were checked in model house, wall manufactured with styroform and grass wool was affected easily by the changes of outdoor temperature. Yellowsoil, the mixed board of yellowsoil and sawdust, and laminated lumber, which have high volume specific heat capacity, were not affected much. The rates of overall heat transmission were much better in styroform and grasswool, but the adiabatic properties were much higher in yellowsoil board and the mixed board of yellowsoil and sawdust. The results showed that the insulating material can be developed using yellowsoil and wood, which are nature friendly materials.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.308.1-308.1
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• 2013

여름철 건축물의 냉방 부하 저감 및 자동차 실내의 온도 상승을 억제하기 위하여 일반적으로 단열필름이 사용되고 있다. 실제 시중에 유통되고 있는 단열필름은 크게 유기물 기반의 제품과 무기물 기반 제품으로 나뉘고 있다. 본 연구에서는 유기물 기판의 단열 필름은 내구성이 거의 없기 때문에 무기물 기반의 제품을 위주로 연구를 진행하였다. 단열 필름의 단열 효과가 어느 정도인지를 정확히 알기 위하여 UV-Vis 스펙트럼 분석을 실시하였다. 항온 항습 장치를 이용하여 고온고습 조건에서 무기물 기반의 단열 필름의 성능 변화를 통하여 내구성 실험을 실시하였다.

• Journal of the Korean GEO-environmental Society
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• v.20 no.4
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• pp.11-16
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• 2019

The low temperature and temperature difference (variation) may cause to deteriorate the integrity of tunnel constructed in cold region. An insulation material was developed and applied to the tunnel lining surface to keep the temperature of tunnel lining constant in spite of temperature variation at outdoor. The lining surface where the insulation material applied showed the less sensitive to temperature variation than non-applied lining surface.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.9
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• pp.825-834
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• 2010

In this study, we investigated the effects of adiabatic walls on natural convection in various rectangular cavities experimentally and numerically. Heat transfer rates were measured for cavities with and without adiabatic sidewalls by varying Grashof number from $1.53\times10^7$ to $1.01\times10^{10}$. Some typical test results were successfully simulated using FLUENT. In the case of very narrow cavities, where the adiabatic walls were very close to each other, it was difficult to perform experiments; therefore, FLUENT simulations were performed. The existing heat transfer correlations for rectangular cavities were well predicted by the experimental and numerical results. As expected, the effects of adiabatic walls were restricted to the very narrow region near the walls. This study was carried out during the development of an analogy experimental method in which heat-transfer systems are replaced with mass-transfer systems using copper sulfate electroplating systems. The results of this study provide theoretical background of handling adiabatic walls during the design of test facilities.

• Journal of the Korea Institute of Building Construction
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• v.20 no.1
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• pp.53-60
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• 2020

This paper aims to examine the insulation performance of insulated gang form by changing the energy (power) consumption and concrete calorific value to assist in concrete protection in cold weather. According to the test results, the general gang form will generate three times the energy (power) consumption for 12 hours after the concrete is poured. In contrast, insulated gang foam consumed no energy (power) for 21 hours after pouring. The final power consumption was 3.7 times higher than that of the general gang form, confirming the improved performance of insulated gang form with regard to energy (power) consumption. The calorific value examination shows that the calorific value changes significantly according to the change of outside temperature after concrete placement in the case of the general gang form. However, in the case of the insulated gang form, only a slight heat loss occurred in the part of the frame, and it showed a constant heating pattern from the concrete casting to the demolding of the mold.

• Journal of Energy Engineering
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• v.23 no.3
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• pp.82-87
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• 2014

MLI(Multi-layer Insulation) is widely used to get highly insulating on cryogenic system in order to reduce heat loads. MLI for satellites thermal performance is changed by materials and laminated method. In this study, a composite multilayer insulation by application of heat stroage tank performance were compared with materials and laminated to change the way. Experimental methods of the KS C 9805 was used, the composite multilayer insulation and EPS was compared with the insulation performance. A method for analysis of experimental results is the equivalent thickness about CMI and the insulation performance were used to compare thermal conductance. As a results, the equivalnet thickenss and the thermal conductance of the composite multilayer insulation were smaller than the EPS and the thermal performance are more excellent. In addition, the configuration of the composite multilayer insulation materials and laminated method varies depending on the overall heat transfer coefficient was confirmed.

• Journal of the Korean Society of Groundwater Environment
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• v.4 no.3
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• pp.111-115
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• 1997

Discrete fracture model has become one of the alternatives for the classical continuum model to simulate the irregular aspects of the fluid flow and the solute transport in fractured rocks. It is based on the assumptions that the discharge in a single fracture is proportional to the cube of the aperture and the fractured rock can be represented by the statistical assemblage of such single fractures. This study is intended to evaluate the effect of the fracture junction on the cubic law. Numerical solution of flow in junction system was obtained by using the Boundary-Fitted Coordinate System (BFCS) method. Results with different intersection angles in crossing fractures show that the geometry of the junction affects the discharge pattern under the same simulation conditions. Therefore, strict numerical and experimental examinations on this subject are required.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.221-221
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• 2011

최근, 대외적으로 기후변화협약 등 환경에 대한 관심이 높아지면서 국내에서도 온실가스 배출이 큰 에너지의 22.3%를 소비하고 있는 건축물로 인한 환경부하에 관심이 높아지며 고효율 창호의 필요성이 대두되고 있다. 기존의 Low-E (저방사) 유리는 적외선을 반사시켜 단열 유리로서 겨울철에 유리하지만, 건물 전면에 약 50~95% 창호가 사용되는 office 건물에는 여름철 냉방에너지를 많이 사용하기 때문에 단열뿐만 아니라 일사 차폐가 가능한 근적외선 차폐유리가 필요하다. 따라서 본 연구에서는 기존의 Low-E 유리의 문제점인 근적외선 투과문제를 해결하기 위한 기술로서 근적외선 영역을 선택적으로 차폐할 수 있는 박막코팅 물질(흡수체, 반사체) 및 Low-E 대체용 Themochromic 등 나노 박막을 RF magnetron sputtering으로 제조하여 복층유리 구조로 조합해 UV-visible을 측정하였으며 IR Lamp와 태양광 아래에서 온도변화 실험을 진행하였다. 그 결과, 기존 Low-E 복층유리 대비 본 실험에서 사용한 복층유리의 근적외선 차폐효율이 개선됨을 확인하였다.

• Nuclear Engineering and Technology
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• v.26 no.1
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• pp.108-118
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• 1994

A semi-empirical correlation has been developed for adiabatic interfacial friction factors in a long horizontal air-water countercurrent stratified flow conditions. Using a pipe and duct test sections, a series of experiments hate been conducted varying non-dimensional water depth and flow rates of air. On the basis of simultaneous measurement of the main flow parameters in a horizontal pipe and a duct, a semi-empirical correlation for the interfacial friction factor in a stratified flow regime has been developed employing a new concept of surface roughness in wavy flow. A total of 201 data point, including 15 concurrent pipe flow test data of others, have been used in the present analysis. A comparison between the data and the predictions of the present correlation shows that the agreement is within $\pm$30%.