• Journal of ILASS-Korea
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• v.8 no.1
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• pp.9-15
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• 2003

The liquid phase LPG injection (LPLI) system is considered as one of the next generation fuel supply systems for LPG, vehicles, since it can accomplish the higher power, higher efficiency, and lower emission characteristics than the existing mixer type fuel supply system. However, during the injection of liquid LPG fuel into the inlet duct of an engine, a large quantity of heat is extracted due to evaporation of fuel. A problem is that the moisture in the air freezes around the outlet of a nozzle, which is called icing Phenomenon. It may cause damage to the outlet nozzle of an injector. The frozen ice deposit detached from the nozzle also may cause a considerable damage to the inlet valve or valve seat. In this work, the experimental investigation of the icing phenomenon was carried out. The results showed that the icing phenomenon and process were mainly affected by humidity of inlet air instead of the air temperature in the inlet duct. Also, it was observed that the icing occurs first in the inlet of a nozzle, and grows considerably at the upper part of the nozzle inlet and the opposite side of the nozzle entrance. An LPG fuel, mainly consisting of butane, has lower latent heat of vaporization than that of propane, which is an advantage in controlling the icing phenomenon.

• Journal of Bio-Environment Control
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• v.18 no.4
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• pp.460-467
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• 2009

This research was conducted for the purpose of investigating the influence substrates addition such as germanium or Granite porphyry gravel have on the growth of foliage, on the inorganic compositions of leaves as well as on root activity, in order to discover effective means of introducing plants to the indoors. Syngonium podophyllum, Dracaena sanderiana, Epipremnum aureum and Hedera helix were used as study subjects to which soil (mixed top-soil: Sunshine Mix No. 2, USA), tap water, tap water with germanium (300g), tap water with Granite porphyry gravel (300g) were added respectively and formulated. Studies on growth variations according to substrates addition indicate that growth of Syngonium podophyllum was most sluggish under tap water only treatment. Plant growth was most active under geranium-gravel treatment. In the case of Dracaena sanderiana, treatment of substrates addition had no meaningful influence on plant growth. However, the growth of Epipremnum aureum and Hedera helix was also shown to be most active under geranium-gravel treatment. Geranium-gravel treatment was shown to be particularly beneficial for root length, number of roots and dry weight. Root activity was analyzed on ten day intervals and there was discernable difference in the root activity of all the plants according to the varying treatments. In the case of the Syngonium podophyllum, the root activity was sluggish in all three types of treatment on the 10th day but improved gradually. On the 30th to the 50th day of the experiment, the root activity was found to be best under the Granite porphyry gravel treatment. In the case of the Dracaena sanderiana, the root activity was most active under the geranium-gravel treatment from the 10th to the 40th day but deteriorated from the 50th day. However, there was no significant different in all three treatments from the 60th day onwards. Analysis of the inorganic components of the leaves indicates that, while Ca and Mg were higher in the geranium than in the Granite porphyry gravel, they do not directly influence the content of inorganic components in the leaves. The results indicate that Epipremnum aureum and Hedera helix grow better under hydro-culture than when grown in soil and growth under hydro-culture is shown to increase when germanium is added to tap water.

• Journal of The Korean Association For Science Education
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• v.18 no.1
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• pp.71-82
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• 1998

The main purpose of Iowa Chautauqua Program(ICP) and Iowa-Scope, Sequence. and Coordination (Iowa-SS&C) was to educate K-12 science teachers so that they could teach science in a human context using the constructivist strategies. The major task for the participating teachers to perform was to develop modules with the emphasis on STS and constructivist approach. which were supposed to be taught in the respective classrooms. Teachers worked together for two weeks for the development of modules during the summer, and attempted the modules with their students. The participating teachers met regularly during the autumn semester to share and reflect their experiences and obtain additional information on science education reform and its implications. During the winter break. the teachers improved and extended the STS modules. The Iowa Chautauqua Program and Iowa-SS&C had two important implications for Korean science education. First, they made the most of the resources they had in order to provide the practicing teachers with recent research findings on the nature of science. science learning and teaching, that is. the constructivist approach. Second, they emphasized both cooperation of teachers and long-term training to realize the reform in school science education.

• Journal of ILASS-Korea
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• v.14 no.4
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• pp.147-152
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• 2009

Since a liquid-phase LPG injection system allows accurate control of fuel injection and increase in volumetric efficiency, it has advantages in achieving higher engine power and lower emissions compared to the mixer type LPG supplying system. However, this system also leads to an unexpected event called icing phenomenon which occurs when moisture in the air near the injector freezes and becomes frost around the nozzle hole due to extraction of heat from surrounding caused by instant fuel vaporization. As a result, it becomes difficult to control air/fuel ratio in engine operation, inducing exacerbation of engine performance and HC emission. One effort to mitigate icing phenomenon is to attach anti-icing injection tip in the end of nozzle. Therefore, in this study, the effect of engine operation parameters as well as surrounding conditions on icing phenomenon was investigated in a bench test rig with commercially-used anti-icing injection tips. The test results show that considerable ice was deposited on the surface near the nozzle hole of the anti-icing tip in low rpm and low load operating conditions in ambient air condition. This is because acceleration of detachment of deposited ice from the tip surface was induced in high load, high rpm conditions, resulting in decrease in frost accumulation. The results of the bench testing also demonstrate that little or no ice was formed at surrounding temperature below a freezing point since the absolute amount of moisture contained in the intake air is too small in such a low temperature.

• Journal of the Korean Institute of Gas
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• v.11 no.4
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• pp.12-16
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• 2007

The fuel pressure regulator mounted on CNG vehicles is used to maintain a constant pressure in the fuel injection system. It needs precise fuel pressure control to obtain benefits of high efficiency and low emissions in CNG vehicles. In this study, a high pressure test rig for the performance evaluation of CNG regulators was introduced. Two different CNG regulators were tested and compared each other at various test conditions. Results showed that dynamic response and creep characteristics are directly effected by the valve assembly design. Gas temperature was dramatically dropped at hish supply pressure conditions, so that effective design for coolant bowl is needed to prevent icing problem.

• Cartoon and Animation Studies
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• s.32
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• pp.245-261
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• 2013

This paper analyzes films by director Tarsem Singh in relation to the theory of the sublime. The medium of film works in dimensions of both spectacle and narrative. Tarsem's strength mainly comes from spectacle. The visual style of Tarsem is unique and undeniably beautiful, but in a strange and magnificent way, rather than sweet and pleasant. If you accept the premises of Kant and Lyotard that the beautiful is a positive pleasure and the sublime is a negative pain, Tarsem's spectacle is certainly closer to the sublime than the beautiful. The Fall proves the director's ability in both spectacle and narrative. The spectacle of this film is so overwhelmingly huge, and vivid, it easily surpasses spectators' maximum capacity of imagination, which leaves the spectators in awe. Spectacle tends to hinder thinking thus obstruct the flow of narrative, but at the same time it blocks rational suspicion about the narrative. The spectacle of the Fall works as the power to immerse the spectators into the internal logic of the film. Since the spectators are deeply moved by the spectacle, they willingly follow the narrative of the film, the tragic adventure of the heroes which again gives the audience deep catharsis.