• Journal of the Korean GEO-environmental Society
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• v.12 no.11
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• pp.51-57
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• 2011

The calcium hydroxide($Ca(OH)_{2}$) which is flowed into the deteriorated tunnel by groundwater is reacted with carbon dioxide($CO_{2}$) and the vehicle's exhaust gas ($SO_{3}$). So its by-products are precipitated at the drainage pipe and these cause the drainage clogging. Most by-products are composed of $CaCO_{3}$ with calcite from a chemical experiment. The purpose of this study is mainly focused on comparison of attachment on each material of drainage pipe (teflon-coated steel pipe, silicon-Oil coated pipe, acrylic pipe and PVC pipe). The test was progressed to disembogue the CaO aqueous solution and tunnel outflow into each of the pipes. The experimental results show that the most produced scale pipe is PVC material and the followings are Acrylic pipe, Silicon-Oil coating pipe and Teflon coating pipe. But the long-term test results showed that teflon-coated steel pipe had a problem with durability because soil which was contained in the tunnel outflow occurred detachment of coating and corrosion of the steel pipe.

• The Journal of the Korea institute of electronic communication sciences
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• v.3 no.1
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• pp.31-38
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• 2008

Tanker oil outflow accident and nitric acid 2000 ton of our country T'aean offing fire etc. vessel sinking and the national treasure 1 good-natured person swunglyey bites to tell the truth the many misfortune occurred in recent times and the numerous casualty occurred. Consequently the righteousness where the preparation and misfortune will occur became the VIP where the preparation and misfortune will occur became the VIP where the information transmission which is quick is important about disaster. Consequently establishes the information transmission system which is quick in the area where the effect of misfortune is worried from observation perceives a disaster construction system development the merger of state radio network with under contributing which minimizes the loss of property and life of the citizen who is caused by with disaster damage boil.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.778-781
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• 2002

Durability of rubber dust cover in the ball joint for automotive suspension parts were analyzed by FEM and compared with experimental data. Upper open area of ball joint is sealed by dust cover for preventing outflow of the lubricating oil and intrusion of send, dust, water, etc. This rubber cover undergoes repeated loadings such as tension and compression while the car is running. Analysis about rubber material needs to consider every kinds of nonlinearities arise in finite element analysis, which are geometric nonlinearity due to large displacement and small strain, materially nonlinearity and nonlinear boundary condition such as contact. So in the study, the deformation behavior of dust cover was analysed by using the commercial finite element program MARC. This program could solve these kinds of nonlinear analysis accurately. Finite element model of dust cover is considered as 3-dimensional half model based on 2-dimensional axisymmetric model. Material property of rubber was modeled by Ogden model and input data for calculation takes form uniaxial tension test of rubber specimen, The final object of the study is obtaining the design specification of dust covers and the result of analysis should be a useful data to design of rubber

• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.695-702
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• 2003

In this study, an experimental apparatus has been designed and set-up to analyse the dissociating phenomena of hydrate in porous rock using electric heating method supplied at downhole. The electric heat injecting experiments have been performed to investigate the heat transfer within the core, the dissociating phenomena of hydrate, and the productivities of dissociated gas and water. These experiments were under constant heat injecting method as well as preheating methods. From the experimental results, it is seen that the hydrates is dissociated along the phase equilibrium curve and dissociation of hydrate is accelerated with heat. The injected heat is consumed for the dissociation and also it is lost together with outflow of the dissociated gas and water. From the investigation of gas producing behavior for various heat injecting methods, as the injected heat is greater, dissociation is accelerated faster at outlet and hence the initial gas production becomes higher. Also, it is shown that the initial gas productivity under the constant heating method is better, however, the energy efficiency is low because of smaller amount of the produced gas comparing to the amount of heat injected. In the experiments of preheating method, it was seen that gas production only initial stage is different with the preheating time, but the producing behaviors of gas production are similar.

• Journal of Ocean Engineering and Technology
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• v.24 no.2
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• pp.25-33
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• 2010

Collision between vessels may lead to structural damage and penetration of hulls. The structural damage of a hull may eventually bring about global collapse of the hull girder and outflow of oil, which would contaminate seawater. Therefore, various regulations require the strength of a vessel after collision to satisfy given criteria, and owners usually request collision analyses to confirm the structural safety of their vessels. In the process of designing a vessel to satisfy the collision strength criteria, the strength has been assessed mostly by conducting collision analyses using numerical techniques, such as dynamic, non-linear, finite-element analysis. Design is an inherently iterative process during which many changes are necessary due to the endless needs for reinforcement and modification. Numerical techniques are not adequate for coping with a situation in which collision analysis is frequently required to provide the revised results that reflect the repetitive changes in designs. Numerical techniques require a lot of time and money to conduct in spite of recent improvements in computing power and in the productivity of modeling tools. Therefore, in this paper, an analytical technique is introduced and a collision problem is idealized and simplified using reasonable assumptions based on appropriate background. The technique was applied to an example of an actual FPSO and verified by comparing the results with results from the numerical technique. A good correlation was apparent between the results of the analytical and numerical techniques.

• Korean Journal of Computational Design and Engineering
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• v.10 no.5
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• pp.375-379
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• 2005

Durability of rubber dust cover in the ball joint for automotive suspension parts is analyzed by FEM and compared with experimental data. Upper open area of ball joint is sealed by dust cover for preventing outflow of the lubricating oil and intrusion of send, dust, water, etc. This rubber cover undergoes repeated loadings such as tension and compression while the car is running. Analysis about rubber material needs to consider every kinds of nonlinearities arise in finite element analysis, which are geometric nonlinearity due to large displacement and small strain, materially nonlinearity and nonlinear boundary condition such as contact. The deformation behavior of dust cover is analysed by using the commercial finite element program MARC. In the study, this program could solve these kinds of nonlinear analysis accurately. Finite element model of dust cover is considered as 3-dimensional half model based on 2-dimensional axisymmetric model. Material property of rubber is modeled by Ogden model and input data for calculation takes form uniaxial tension test of rubber specimen. The final object of the study is obtaining the design specification of dust covers and the result of analysis should be a useful data to design of rubber cover.

• The Korean Journal of Malacology
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• v.31 no.3
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• pp.213-220
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• 2015

After oil outlow accident of Hebei spirit in December 7, 2007, the motality of manila clam, Ruditapes philippinarum in the west coast of South Korea, was significantly increased from 9.2% in April, 2007 to 22.4% in April 2008. Although the mortality was about 10% in the tidal flat of Geunso Bay and Cheonsu Bay, Incheon and Gyeonggi-do, the values was significantly high about 30% in water coast of Taean, Boryeong and Seosan in where the spilled oil was getting into fishery zone. However, the mortality in water coast of Taean, Boryeong and Seosan was decreased from 22.4% in 2008 to 6.0% in 2009. Also, we found that the mortality in contaminated and non-contaminated water zones was both slightly increased from 6.0 in 2009 to 8.6% in 2010, Therefore, these results are indicating that the significant high mortality observed in water coast of Taean, Boryeong and Seosan at April, 2008 was due to the crude oil accident outflow from tanks of Hebei spirit. Although the mortality of manila clam was significantly decreased in middle west coast of South Korea after the accident of Hebei spirit in December, 2007, the annual production of manila clam in South Korea was sustainedly from 27,459 ton in 2007, 36,302 ton in 2008, 40,392 ton in 2009, to 36,248 ton in 2010. In the production of manila clam by regional groups, the amount in sea coast of Chungnam, where was damaged by crude oil, was significantly decreased from 10,598 ton in 2007 to 5,048 ton in 2008, but then was significantly increased to 7,065 ton in 2009, and to 12,921 ton in 2010. However, in sea coast of Jeonnam that was not damaged by crude oil, the amount was significantly increased from 1,252 ton in 2007 to 12,248 ton in 2008, but then was significantly decreased to 9,566 ton in 2009, and to 2,770 ton in 2010. Therefore the results are suggesting that a increasing of the total annual production of manila clam in South Korea in 2008 when was 1 year after the oil accident of Hebei spirit was due to increasing of clam production in a coast of Jeonnam in where was not damaged by crude oil.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.22 no.6
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• pp.437-445
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• 2010

There is increasing interest, on the global basis, in the operation of ocean surface radars for measurement of coastal sea surface conditions to support environmental, oceanographic, meteorological, climatological, maritime and disaster mitigation operations. In south Korea, ocean surface radars are operating to monitoring oil spill, outflow from dike or preventing from safety-accidents in the 6 regions (16 radial sites) by main frequency about 13, 25 and 42 MHz until the present. However, that ocean surface radars have been operated on an experimental spectrum basis. In the results of 3~50 MHz band domestic analysis to improve the regulatory status of the spectrum used by oceanographic radars, it was demonstrated that sufficient frequency bands are available for oceanographic radars on the frequency band above 20 MHz. It is difficult to deploy and operate oceanographic radars in the sub-bands below 20 MHz except for 13 MHz band. For using HF ocean surface radars one should understand the spectrum environment in Korea and should prepare a suitable operating system and data processing techniques.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.24 no.3
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• pp.113-120
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• 2018

The one-way gas valve developed in this study was designed to prevent the breakage of packages from increased internal pressure, which is a problem in packaged Kimchi, and simultaneously reduce the outflow of the offodor release. The effect of the one-way gas valve on the headspace atmospheric compositions was investigated in the packaging system. The changes of atmospheric compositions and quality factors of Kimchi, such as $CO_2$ accumulation, pH, titratable acidity, and salinity, were measured during a 4-week storage period at $4^{\circ}C$. The Kimchi package with the one-way gas valve dramatically reduced pressure build-up in the pouch by allowing the controlled flow of gas to the atmosphere. In addition, the package design allows the possibility of controlling the gas generated from Kimchi by adjusting the viscosity of the open pressure control oil. The one-way gas valve did not affect the sensory characteristics of Kimchi products during the storage period. Furthermore, the deodorizing capability of the activated carbon contained in the one-way gas valve effectively reduced the off-odor of Kimchi products released along with carbon dioxide. The novel one-way gas valve is considered to be an active packaging system that can solve major problems of expansion and off-odor leakage in the packaging of Kimchi.

• Journal of the Society of Disaster Information
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• v.18 no.1
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• pp.1-9
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• 2022

Purpose: In this study, we used hydrophilic waterstop used in geosynthetics vertical barrier system to evaluate the performance of impermeability under sealing conditions. Method: ASTM D5887 and ASTM D6766 were applied to determine the capability of the connection during the geosynthetics vertical barrier system. Hydrophilic waterstop was saturated in each solution and the weight, thickness, and volume changes were analyzed over elapsed time. Hydrophilic waterstop was installed at the geosynthetics vertical barrier system connection to evaluate the permeability characteristics. Results: As the expansion reaction time of hydrophilic waterstop increased relatively under saline conditions, the decrease in permeability also showed a smaller decrease in fresh water. Furthermore, the method of engagement of the geosynthetics vertical barrier system showed somewhat better performance of the impermeability due to the large pressure resistance caused by the roll joint type than interlock type. Conclusion: In urban pollutants, which can estimate the outflow of pollutants such as oil storage facilities and industrial complexes, proactive response technologies that can prevent the contaminant diffusion can significantly reduce the damage.