• Corrosion Science and Technology
• /
• v.6 no.6
• /
• pp.308-310
• /
• 2007

The owner of underground metallic structures (gas pipeline, oil pipeline, water pipeline, etc) has a burden of responsibility for the corrosion protection in order to prevent big accidents like gas explosion, soil pollution, leakage and so on. So far, Cathodic Protection(CP) technology have been implemented for protection of underground systems. The stray current from DC subway system in Korea has affected the cathodic protection (CP) design of the buried pipelines adjacent to the railroads. In this aspect, KERI has developed a various mitigation method, drainage system through steel bar under the rail, a stray current gathering mesh system, insulation method between yard and main line, distributed ICCP(Impressed Current Cathodic System), High speed response rectifier, restrictive drainage system, Boding ICCP system. We installed the mitigation system at the real field and test of its efficiency in Busan and Seoul, Korea. In this paper, the results of field test, especially, distributed ICCP are described.

• Proceedings of the KSME Conference
• /
• 2001.06a
• /
• pp.573-578
• /
• 2001

For the corrosion protect ion of the natural gas transmission pipelines, two methods are used, cathodic protection and coating technique. In the case of cathodic protection, defects are embrittled by occurring hydrogen at the crack tip or material surface. It is however very important to evaluate whether cracks in the embrittled area can grow or not, especially in weld metal. In this work, on the basis of elastic plastic fracture mechanics, we performed CTOD test ing with varying test conditions, such as the potential and current density. The CTOD of the base steel and weld metal showed a strong dependence of the test conditions. The CTOD decreased with increasing cathodic potential and current density. The morphology of the fracture surface showed quasi-cleavage. Hydrogen introduced fractures, caused by cathodic overprotection.

• Corrosion Science and Technology
• /
• v.9 no.5
• /
• pp.201-208
• /
• 2010

Epoxy coatings cured by different amine based curing agents have been prepared. Atomic force microscopy (AFM) has been used to monitor the surface topology changes of epoxy coatings before and after hygrothermal cyclic test. The glass transition temperature ($T_g$) and coefficient of thermal expansion (CTE) of the epoxy coating were measured by Thermo-mechanical Analysis (TMA). The Electrochemical impedance spectroscopy (EIS) with hygrothermal cyclic test has been introduced to evaluate the corrosion protection of the epoxy coatings. In conclusion, thermal properties of epoxy coatings were in good agreement with the results of corrosion protection of epoxy coated carbon steel obtained result by EIS with hygrothermal cyclic test. The relationship between thermal properties, surface roughness changes and corrosion protection of epoxy coatings are discussed in this study.

• Proceedings of the KSME Conference
• /
• 2004.04a
• /
• pp.1570-1575
• /
• 2004

In order to evaluate the performance of fire-fighting agents used to protect structures from heat and fire damages, the thermal characteristics of fire-protection foams are experimentally investigated. The current research focuses on the destruction of a fire-fighting foam subjected to heat radiation. A simple repeatable test for fire-protection foams subjected to fire radiation is developed. This test involves foam generation equipment, a fire source for heat generation, repeatable test procedures, and data acquisition techniques. Results of the experimental procedure indicated that each thermocouple within the foam responded in a similar manner and gradually to a temperature of $15^{\circ}C{\sim}20^{\circ}C$. At this point, each trace generally rises to a temperature of approximately $90^{\circ}C$. The temperature gradient in the foam as time passes increases with increased foam expansion ratio. In addition, it is determined that the temperature gradient along the foam for depth decreases with increased foam expansion ratio.

• Fire Science and Engineering
• /
• v.24 no.6
• /
• pp.89-97
• /
• 2010

In recent fire protection system, the pipings should be light weighted, seismic proof and wrought with non-welding method. The light weighted stainless steel pipes and fittings, satisfying these requirements, are already used as a fire protection system in Germany, Netherland, Taiwan, Australia, United States and Japan. Accordingly, performance evaluation tests were carried out to determine whether or not the fittings can be used in the pipings. As the performance evaluation tests, we conducted vibration test, water hammering test, bending test and fire test. With the results of the tests, we concluded that the fittings can be used in the fire protection system, and that the life expectancy of the fittings exceeds that of buildings.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.22 no.1
• /
• pp.36-45
• /
• 2014

Pedestrian to vehicle traffic accidents show a very high mortality rate compared to the frequency of occurrence. In order to improve the pedestrian protection performance of the vehicle, the korean government added a "pedestrian safety" entry from the year 2007. The performance for pedestrian protection of current vehicles gradually improved compared to the past, but it is still insufficient. It was found that the pedestrian protection performance was very weak, such as the top of the bonnet, the A-pillar and under the front windshield. A application of an active hood and pedestrian protection airbags can be countermeasures for these weak points of pedestrian safety. The active hood and pedestrian protection airbags are designed and manufactured to apply to the top of the hood and to the bottom of the windshield. The manufactured system is equipped in a test vehicle and evaluated based on the Korea New Car Assessment Program(KNCAP) test procedures for the performance of pedestrian safety. As a result, the outstanding effect of pedestrian protection has been achieved by the active hood and the pedestrian protection airbag. The rates of pedestrian injury are reduced by 82.2% and 95.4%, respectively.

• Journal of Korean society of Dental Hygiene
• /
• v.14 no.5
• /
• pp.673-680
• /
• 2014

Objectives : The purpose of this study is to investigate the awareness and performance towards the dental radiation protection behaviors in dental institutions in Busan and Gyeongnam. Methods : Two hundred and one dental medical institutions in Busan and Gyeongnam participated in the survey from March 10 to April 4, 2014. The data were analyzed using SPSS 19.0 for ${\chi}^2$ test, t-test, ANOVA, and multiple regression analysis. Results : There were significant differences in the awareness and performance towards the radiation protection behaviors according to age, monthly income, and type of hospital(p<0.05). Protective equipment influenced on the awareness and performance of dental staff and patients(p<0.001). The important variables on dental radiation protection included protection facility and education of protective equipment. It is found the variable to affect the performance of dental radiation protection was protection facility, wearing of protective device staff and patients, education on RSM. Conclusions : These results can provide the basic data for the effective dental radiation safety management and improvement for the dental institutions.

• Mycobiology
• /
• v.30 no.1
• /
• pp.37-40
• /
• 2002

The susceptibility of radiata pine sapwood to fungal attack and the ability of selected fungicides to control colonization of sapstain and mold fungi on green radiata pine sapwood were evaluated. Radiata pine sapwood was highly susceptible to fungal staining, suggesting that prompt application of fungicides after sawing is essential for preventing fungal colonization. The ability of commercial fungicides to prevent fungal discoloration on radiata pine sapwood was assessed using an accelerated 6-week test on small samples in the laboratory, and in field tests using bulk-piled boards exposed outdoors for 6 weeks during summer rainy season. In laboratory tests, Hylite extra provided excellent protection against fungal discoloration even at the lowest concentrations. Hylite clear, Britewood S, and NP-1 Plus provided good short-term protection(2 to 4 weeks), but higher chemical loadings were, required for long-term protection(6 weeks). Woodguard produced little or no protection over the test periods. In field tests, Kathon 893 provided markedly superior protection at the concentration of 0.5 percent or higher. NP-1 Plus provided relatively good protection at all concentrations evaluated. Hylite extra was effective only for short-term protection(2 to 4 weeks) at all concentrations tested, but higher solution strengths were needed for longterm protection.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
• /
• 1997.11a
• /
• pp.423-438
• /
• 1997

Today's building and fire prevention codes are mostly prescriptive. Prescriptive codes are based on major fires in earlier years that created a need for specific building provision. These codes provide a minimum level of safety. As the general and engineering uses of computers have increased over the years, so has use of computers in the fire protection engineering. This has allowed fire protection engineers to develop alternative approaches to solve today's fire protection problems or to evaluate the performance of a specific fire safety goal. A performance based approach to building and fire codes involves the following: 1) identifying specific goals, such as, safely getting out of the building in 10 minutes, 2) obtain conceptual approval from authorities, 3) define performance level, 4) develop design solutions and identify tools such as, fire tests, models, or methods, to demonstrate that a design will meet the fire protection objective 5) test solutions, 6) present test method and results to the authorities. Some people in the fire protection community consider this to be nothing more than an intellectual exercise, while the others view it as a way to reduce expenses on large project$^4$ Others in fire protection community view this as a way to refine the design process to design fire protection systems to better protect the fire hazards. This paper will focus on application of these tools, specifically computer fire models, to actual cases such as: design of a smoke control system heat transfer analysis and egress of building occupants during potential fires.

• Fire Protection Technology
• /
• s.13
• /
• pp.12-17
• /
• 1992

This report is announced about test results of manually actuated signaling boxes(manual call points) and audible signal appliances (alarm bell), so as to occupants, inhabitants or persons di-rectly concerned with the implementation and direction of emergency action initialation is the area protected. The testing plan was progressed devided by three testing items, external appearance inspec-tion, performance test and environment proof test. The purpose of this report is to analyze the characteristics of products.