• Journal of the Korean Chemical Society
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• v.52 no.1
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• pp.84-95
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• 2008

In this study, preconceptions held by chemistry major secondary school science teachers were searched in relation to explanations of water evaporation phenomena with phase equilibrium diagrams. 25 chemistry major science teachers were selected to complete questionnaires developed in this study and 6 among of them were selected to participate in follow-up interviews. Among these, 10 participants were selected for an evaluation of the change of their preconceptions through lessons developed in this study. From the results, it was found that many teachers believed that the phase equilibrium diagram could not explain water evaporation phenomena. They also thought that there was no relation between vapor pressure and the vertical axis of the phase equilibrium diagram. However, after the lessons in earth science, they recognized that the vapor pressure curve of the phase equilibrium diagram could be explained by adopting a saturated vapor curve. Because they had known the process of application the conceptions of saturated situation, nonsaturated situation, process of equilibrium movement in saturated vapor curve. They could understand natural phenomena such as evaporation with the phase equilibrium diagram through a change in their conceptions as guided from science lessons integrating earth science and chemistry.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.129.2-129.2
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• 2010

As a part of the government renewable energy policy, KOWEPO is constructing 300MW IGCC plant in Taean. IGCC plant consists of gasification block, air separation unit and power block, which performance test is separately conducted. Overall performance test for IGCC plant is peformed to comply with ASME PTC 46. Major factors affected on the overall efficiency for IGCC plant are external conditions, each block performance(gasification, ASU, power block), water/steam integration and air integration. Performance parameters of IGCC plant are cold gas efficiency, oxygen consumption, sensible heat recovery of syngas cooler for gasification block and purity of oxygen, flow amount of oxygen and nitrogen, power consumption for air separation unit and steam/water integration among the each block. The gas turbine capacity applied to the IGCC plant is 20 percent higher than NGCC gas turbine due to the low caloric heating value of syngas, therefor it is possible to utilize air integration between gas turbine and air separation unit to improve overall efficiency of the IGCC plant and there is a little impact on the ambient condition. It is very important to optimize the air integration design with consideration to the optimized integration ratio and the reliable operation. Optimized steam/water integration between power block and gasification block can improve overall efficiency of IGCC plant where the optimized heat recovery from gasification block should be considered. Finally, It is possibile to achieve the target efficiency above 42 percent(HHV, Net) for 300MW Taean IGCC plant by optimized design and integration.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.685-693
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• 2021

This study examined the fire risk of the region in Goyang City using the spatial information data of buildings. The economic damage by industry was assessed according to the probability of fire risk. The study area was confined to Goyang-si, Gyeonggi-do, and the same fire risk reduction rate was applied to each region for the convenience of analysis. The possibility of fire was derived based on the buildings' density and usage in the area by National GIS building-integrated information standard data. The calculation of economic damage by industry in Goyang City due to the fire risk was calculated by combining the Goyang-si industry-related model produced by matching with 30 industrial categories in Input-Output Statistics of Korea Bank and 20 industrial categories in the Goyang-si business survey and the possibility of fire. The basic scenario of production impossibility during six months and business loss due to fire was established and analyzed based on the supply model. The analysis showed that Ilsan-dong-gu, Ilsan-seo-gu, and Deokyang-gu suffered the most economic damage. The "electricity, gas, steam, and water business" showed the greatest loss by industry.