• Proceedings of the Korea Air Pollution Research Association Conference
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• 2002.11a
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• pp.207-208
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• 2002

휘발성 유기화학물질 (VOCs)이 인체의 건강에 미치는 영향은 아직까지도 명확하게 밝혀지진 않았지만 대부분의 물질이 재실자에게 자극과 불쾌감을 유발하며, 여러 종류의 발암성 물질을 포함하고 있는 것으로 알려지고 있다 휘발성 유기화학물질 중에서 80% 정도가 인체의 호흡기관을 자극하고 눈의 통증이나 자극을 유발하며, 이중에서 25% 정도는 발암성 물질로 파악되고 있다. (중략)

• The Korean Journal of Air & Space Law and Policy
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• v.24 no.2
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• pp.187-210
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• 2009

Space law(or outer space law) and the law of the sea are branches of international law dealing with activities in geographical ares which do not or do only in part come under national sovereignty. Legal rules pertaining to the outer space and sea began to develop once activities emerged in those areas: amongst others, activities dealing with transportation, research, exploration, defense and exploitation. Naturally the law of the sea developed first, followed, early in the twentieth century, by air law, and later in the century by space law. Obviously the law of the sea, of the air and of outer space influence each other. Ideas have been borrowed from one field and applied to another. This article examines some analogies and differences between the outer space law and the law of the sea, especially from the perspective of the legal status, the exploration and exploitation of the natural resources and environment. As far as the comparisons of the legal status between the outer space and high seas are concerned the two areas are res extra commercium. The latter is res extra commercium based on both the customary international law and treaty, however, the former is different respectively according to the customary law and treaty. Under international customary law, whilst outer space constitutes res extra commercium, celestial bodies are res nullius. However as among contracting States of the 1967 Outer Space Treaty, both outer space and celestial bodies are declared res extra commercium. As for the comparisons of the exploration and exploitation of natural resources between the Moon including other celestial bodies in 1979 Moon Agreement and the deep sea bed in the 1982 United Nations Convention on the Law of the Sea, the both areas are the common heritage of mankind. The latter gives us very systematic models such as International Sea-bed Authority, however, the international regime for the former will be established as the exploitation of the natural resources of the celestial bodies other than the Earth is about to become feasible. Thus Moon Agreement could not impose a moratorium, but would merely permit orderly attempts to establish that such exploitation was in fact feasible and practicable, by allowing experimental beginnings and thereafter pilot operations. As Professor Carl Christol said until the parties of the Moon Agreement were able to put into operation the legal regime for the equitable sharing of benefits, they would remain free to disregard the Common Heritage of Mankind principle. Parties to one or both of the agreements would retain jurisdiction over national space activities. In so far as the comparisons of the protection of the environment between the outer space and sea is concerned the legal instruments for the latter are more systematically developed than the former. In the case of the former there are growing tendencies of concerning the environmental threats arising from space activities these days. There is no separate legal instrument to deal with those problems.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.10
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• pp.1038-1048
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• 2010

Radiation exposures of an astronaut during the space travels to the International Space Station(ISS) of the Soyuz and the Moon of the Apollo, were calculated considering the altitude, boarding time, period of stay, kinds of spaceships and space suits. The calculated radiation exposures decrease dramatically according to the thickness of the shielding by the wall of the spaceships and by the space suits. For the space travel to the ISS of Soyuz at Low Earth orbit, the thickness of the spaceship required to optimally reduce the radiation exposure is 3 cm. For the Extravehicle Mobility Unit(EMU) the exposures are minimized at 4 cm of the aluminized Mylar and 5 cm of the Demron, respectively. The aluminized Mylar showed better radiation shielding than the Demron which contains the high Z materials. The radiation exposures of an astronaut were $4.2\times10^{-6}$ Sv for the ISS travel and $4.3\times10^{-5}$ Sv for the Moon explore. The high concentration of the high energy proton flux at the surface of the Moon results in high radiation exposure. The calculation scheme and results of this study can be used in the design of the shielding performance of a spaceship and space suits.

• Journal of Bio-Environment Control
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• v.29 no.1
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• pp.9-19
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• 2020

Convective heat transfer is the main component of greenhouse energy loss because the energy loss by this mechanism is greater than those of the other two components (radiative and conductive). Previous studies have examined the convective heat transfer coefficients under natural conditions, but they are not applicable to symmetric thermal screens with zero porosity, and such screens are largely produced and used in Korea. However, the properties of these materials have not been reported in the literature, which causes selectivity issues for users. Therefore, in this study, three screens having similar color and zero porosity were selected, and a mathematical procedure based on radiation balance equations was developed to determine their convective heat transfer coefficients. To conduct the experiment, a hollow wooden structure was built and the thermal screen was tacked over this frame; the theoretical model was applied underneath and over the screen. Input parameters included three components: 1) solar and thermal fluxes; 2) temperature of the screen, black cloth, and ambient air; and 3) wind velocity. The convective heat transfer coefficients were determined as functions of the air-screen temperature difference under open-air environmental conditions. It was observed from the outcomes that the heat transfer coefficients decreased with the increase of the air-screen temperature difference provided that the wind velocity was nearly zero.

• Korean Journal of Plant Resources
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• v.22 no.2
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• pp.152-158
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• 2009

We performed RAPD analysis to investigate the inter-/intraspecific relationships and regional variations of Phragmites japonica and P. communis according to the environmental change. One hundred and fourty nine genetic effective polymorphic bands between 300 bp and 1,900 bp were marked from RAPD PCR with nine oligoprimers. From the RAPD analysis by Nei-Li's genetic distance, the dissimilarity indices among the populations of Phragmites japonica were relatively low from 0.012 to 0.061, and Phragmites communis were also low from 0.033 to 0.095. It showed the close genetic relationships among the same species populations, and both species were distinctly independent with relatively high level of dissimilarity indices (0.043 - 0.132). The obvious genetic markers to distinguish two species were confirmed and those profiles were suggested. From the UPGMA phenogram by RAPD analysis, both species showed the water environment related cluster patterns by distributional regions. RAPD analysis was useful to delimit two species taxonomically and to investigate the genetic relationships among inter-/intraspecific populations.

• Journal of the Mineralogical Society of Korea
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• v.29 no.3
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• pp.131-139
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• 2016

Detailed knowledge on maskelynite, a glassy phase of plagioclase found in shocked meteorites and impact craters, is essential to understand a shock metamorphism. Here, we explore an inhomogeneous shock metamorphism in the lunar meteorite Mount DeWitt (DEW) 12007 with an aim to understand the formation mechanism of maskelynite. Most plagioclase grains in the DEW 12007 partially amorphized into maskelynite with a unidirectional orientation. Back-scattered electron (BSE) images of maskelynite show a remnant of planar deformation fracture possibly indicating that the maskelynite would be formed by solid-state transformation(i.e., diaplectic glass). Plagioclase with flow texture is also observed along the rim of maskelynite, which would be a result of recrystallization of melted plagioclase. Results of Raman experiments suggest that shock pressure for plagioclase and maskelynite in the DEW 12007 is approximately 5-32 GPa and 26-45 GPa, respectively. The difference in shock pressures between plagioclase and maskelynite can be originated from 1) external factors such as inhomogeneous shock pressure and/or 2) internal factors such as chemical composition and porosity of rock. Unfortunately, Raman spectroscopy has a limitation in revealing the detailed atomic structure of maskelynite such as development of six- or five-coordinated aluminum atom upon various shock pressure. Further studies using nuclear magnetic resonance spectroscopy are necessary to understand the formation mechanism of maskelynite under high pressure.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.32 no.5
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• pp.313-322
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• 2019

Recently, there have been frequent occurrences of bridge fires. Fires in cable-supported bridges can damage and brake cables due to high temperatures. In this study, fire scenarios that can occur on cable-supported bridges were set up. In addition, based on the results of vehicle fire tests, a fire intensity model was proposed and cable heat transfer analyses were performed on a target bridge. The analyses results demonstrated that temperature rises were identified on cables with a smaller cross-sectional area. Furthermore, vehicles other than tankers did not exceed the fire resistance criteria. When the tanker fire occurred on a bridge shoulder, the minimum diameter cable exceeded the fire resistance criteria; the height of the cable exceeding the fire resistance criteria was approximately 14 m from the surface. Therefore, the necessity of countermeasures and reinforcements of fire resistance was established. The results of this study confirmed that indirect evaluation of the temperature changes of bridge cables under fire is possible, and it was deemed necessary to further study the heat transfer analysis considering wind effects and the serviceability of the bridge when the cable temperature rises due to fire.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.392-394
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• 2017

In this study, the surface heat transfer coefficient of the 3D model of a thruster regulator in the high temperature and high pressure environment was estimated using the CFD. The thermal barrier coating (TBC) on the surface of the thruster regulator was modeled and the effect of the thickness of the TBC on the temperature of the thruster regulator was investigated. The thickness of the TBC was varied from $100{\mu}m$ to $500{\mu}m$. Results showed that the temperature of the surface and the inside the thruster regulator was lower for the thicker TBS case.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.31 no.3
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• pp.296-305
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• 1995

A numerical study was undertaken to clarify the mechanisms of heat transfer in fluid-particle suspension flows. Such flows, including fluidization, are of considerable industrial importance. The present study uses 2-D numerical computations of collisions of normal incidence between a particle and a wall. By comparing the results using (a) adiabatic boundary conditions on the particle and (b) uniform, elevated temperature conditions on the particle, the contributions of fluid-mediated conduction and particle induced convection were successfully separated. Computational expedience led to the use of a transient conduction thermal layer as the background thermal field for the analysis. The results shows that the effect of particle movement is very small until the particle reaches a distance of one to one half diameter away from the wall. The gas-mediated conduction effect is dominant over the induced gas convection effect when Pe is small and the induced gas convection effect becomes significant as Pe increases.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.4
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• pp.407-414
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• 2017

In this study, a performance evaluation was conducted using a SUS 304 plate applied to low-temperature co-fired coating as a replacement for titanium plates. As a result of computational fluid dynamic analysis, the SUS 304 plate, applied to low-temperature co-fired coating, showed better heat transfer performance than a titanium plate, for 100 micron thickness coating. The result of the experiments using an actual heat exchanger revealed that a coated SUS 304 plate showed better heat transfer performance than a titanium plate. Furthermore, as the degree of corrosion and scale formation of the plate was confirmed through an overhaul inspection, the corrosion resistance of a coated SUS 304 plate was found to be almost the same as that of a titanium plate, and the inhibition effect of scale formation by sea water was better with a coated SUS 304 plate.