• Proceedings of the KIEE Conference
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• 1998.07e
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• pp.1752-1754
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• 1998

Recently the research about electron transport characteristic and energy distribute function in mixture gases within Helium, has been used and developed widely as industrial quality improvement of extinguish characteristic, electrical dielectric strength ability of application of each species high voltage apparatus, gas plasma etching progress of work to use manufacture of semiconductor, thin film molding by CVD, insulation film to use ultra LSI, etc. This paper analyze electron transport characteristic in the range E/N $1{\sim}60$[Td], pressure $0.1{\sim}6.0$[Torr] by MCS. It is necessary to seek electron drift velocity, diffusion coefficient, lonization coefficients, characteristic energy, mean energy and electron energy distribution function as electron transport characteristic.

• Fire Science and Engineering
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• v.33 no.3
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• pp.51-55
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• 2019

To prevent ozone depletion caused by CFCs, the replacement of Halon with clean agents has been developed in the fire protection field along with refrigerants, detergents, and foaming agents. The alternatives for Halon 1211 have been developed in the portable fire extinguisher area and HCFC-123 is used widely as a clean fire extinguishing agent. The type of expellant gas is important because their own vapor pressure is low. In this study, HCFC-123, HCFC-124, HFC-125, and Novec-1230 were selected as fire extinguishing agents and CO₂, which is expected to improve the fire extinguishing ability, was chosen as the expellant gas. For each agent, experiments changing the agent and CO₂ amount were carried out and HCFC-123 showed a good result, as expected. The extinguisher, HCFC-123 of 1.5 kg, showed the same ability to suppress a class A and B fire as the extinguisher, HCFC-123 of 2.5 kg, which is currently sold on the market. According to this result, the expellant gas has a subsidiary fire extinguish effect. This can reduce the amount of HCFC fire extinguishing agent, which is categorized in the phase-out alternatives, and is a more eco-friendly and economical fire extinguisher than the previous one. This study can also help solve the problems of CO₂ fire extinguishers for class B and C fires, and can be used to extinguish electric and electron facilities fire, which contains large amounts of class A fire combustibles.

• Journal of National Security and Military Science
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• s.13
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• pp.1-41
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• 2016

US 8th Army in the attack on the Western Front was a situation that was frustrated by the 13th Corps Communist army. To this time support this, goals that have been granted to the US 1st Marine Division that initiated the attack in Mupyonri direction, lack the potential to achieve was not decisive. It was a operation specific erroneous judgment that occurred because there was no one accurately grasp the battlefield of the situation the wrong UN Forces Command. Tactical victory can be to maximize the operation outcomes. However, there is no possible failure of the operation is to expand the tactical success. This is because the failure of the operation, because directly linked to the success or failure of the war. Tactical victory can be to maximize the operation outcomes. However, operation specific failure is not it possible to expand the tactical victory. Therefore tactical success of the US 1st Marine Division, can not compensate for operation specific failure of the United Nations Forces Command. However, Chinese Communist Army 9th Corps is obsessed only victory of tactics to annihilate the US 1st Marine Division, by being fixation to the Chosin whole area, it was not possible to run a operational operation. Therefore tactical success df the US 1st Marine Division, Chinese Communist Army 9th Corps is to extinguish the ability to increase the number of the 13th Corps of the Western Front, 8th Army US have contributed to have escaped the crisis. In addition, the US 10th Corps while maintaining the combat force, by an important role to withdraw through the sea, was able to complement the misjudgment of the operation.

• The Journal of the Korea Contents Association
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• v.19 no.9
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• pp.112-121
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• 2019

Title of management of cultural asset architectures made of wood managed by nation or local government is separated and there is a high concern about the disappearance of many national cultural asset architectures by fire. This study investigated the effectiveness of major installed appliances in terms of disaster prevention, and problems by early suppression in the event of fire and by mobilization of fire engines in depth. Also, this study derived problems by conducting an in-depth individual interview on interested parties for installation of fire extinguishing system by related law and to improve system to make realistic maintenance. As a result, it was identified that they have reached the positive aspects of protecting cultural asset architectures from disaster as fire by maintaining and managing facilities by establishing proper disaster prevention measures because they are surrounded by mountain or buildings are contiguous. Wooden cultural asset architectures are often excluded from regulation for installation of fire-fighting facilities under the Fire Services Act because most of wooden cultural assets are detached buildings, occupy small area, and are one-storied architecture. The best method is having extinguishing ability themselves according to the manual by making fire manual as management policy before the outbreak of fire. This study intends to suggest a follow-up study for practical considerations to establish or designate a professional management agency for them to protect important national cultural heritage buildings at the state level before they are destroyed by fire.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.34 no.4
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• pp.233-238
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• 2012

Purpose: To evaluate the effect of silvernanopartilce treated implants on the bone formation and osseointegration. Methods: Silvernanoparticle was produced using an anodic oxidation method. The size of silvernanoparticle ranged from 3.5 nm to 5.9 nm. To check the effect of the capability of osseointegration of silvernanoparticle coated Implant, 32 implants (16 piece of Implant treated with nanoparticle, and 16 piece of Implant was not treated for control) were placed at both the tibia of 8 New Zealand white rabbits. After 4 weeks, 4 rabbits were sacrificed and the removal torque was measured for comparison of the osseointagration ability. Further, 4 rabbits were sacrificed and sliced samples were made. H&E stain was done for microscopic finding. Results: The removal torque of the experimental group was $102.37{\pm}30.54$ N/cm, and the control group was $73.30{\pm}19.97$ N/cm. It was statistically significant (P<0.001). Microscopic finding also shows extinguish results in silvernanoparticle treated implants. Bone formation rate of the experimental group was 43.94% and the control group was 7.58%. It was observed to be statistically significant (P=0.017). Bone to implant contact rate of the experimental group was 58.09%, and the control group was 19.43%. It was found with statistical significance (P<0.001). Conclusion: The silvernanopartilce treated implant shows a better capability of bone regeneration and osseointegration than the non-treated one. Technology to produce smaller particles would make silver more useful and safer.

• Applied Chemistry for Engineering
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• v.34 no.6
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• pp.603-607
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• 2023

Aqueous film forming foam (AFFF) is a critical fire suppression agent used in combating hydrocarbon fires. This type of fire suppressant is highly effective due to its ability to form a protective film, dissipate heat, inhibit combustion, and utilize a blend of chemical substances to extinguish fires. While these properties offer significant advantages in responding to hydrocarbon fires, AFFF is distinct in its deployment as it is dispensed in the form of foam. Therefore, the rheological analysis of AFFF foam using a rheometer plays a crucial role in predicting the spray characteristics of AFFF for combating hydrocarbon fires, and this is closely associated with effective fire suppression. In this study, we conducted rheometer experiments to confirm the non-Newtonian behavior (shear-thinning) of AFFF foam and obtained data on the form's stability. These experimental data are expected to contribute to enhancing the efficiency of fire suppression systems utilizing AFFF.