• Journal of the Korean Society of Safety
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• v.38 no.2
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• pp.44-51
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• 2023

With the recent increase in gas energy use, risk management for explosion accidents has been emphasized. Protective walls can be used to reduce damage from explosions. The KOSHA GUIDE D-65-2018 suggests the minimum thickness and height of protective walls, minimum reinforcement diameter, and maximum spacing of reinforcements for the structural safety of the protective walls. However, no related evidence has been presented. In this study, the blast load carrying capacity of the protective wall was analyzed by the pressure-impulse diagrams while changing the yield strength of the reinforcement, concrete compressive strength, reinforcement ratio, protective wall height, and thickness, to check the adequacy of the KOSHA GUIDE. Results show that failure may occur even with design based on the criteria presented by KOSHA GUIDE. In order to achieve structural safety of protective walls, additional criteria for minimum reinforcement yield strength and maximum height of protective wall are suggested for inclusion in KOSHA GUIDE. Moreover, the existing value for minimum reinforcement ratio and the thickness of the protective wall should be increased.

• Journal of the Korea Institute of Military Science and Technology
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• v.12 no.5
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• pp.571-576
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• 2009

In terms of protective engineering, there are no noticeable researches regarding covered-positions for smaller units in South Korea. So, standards to maintain and build protective facilities for larger units have been applied in ones for smaller units without any adjustment. The previous study was to calculate penetration depth of the concrete walls because the experiment performed indoor. In this outdoor experiment, velocity of projectile impact as one of the other important factors was considered to prove the validity of 30cm concrete wall thickness as effective protective level of the covered-position. Random effects and extraneous variables which could be occurred in outdoors experiment were controlled with statistical techniques. As a result, velocity of projectile impact was significant variable and the given standard, 30cm thickness of concrete walls was as valid as ever.

• Textile Coloration and Finishing
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• v.20 no.4
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• pp.31-42
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• 2008

Tricrecyl phosphate(TCP)-containing polyurea microcapsules were prepared by interfacial polymerization using aromatic 2,4-toluene diisocyanate(TDI) and ethylenediamine(EDA) as wall forming materials. The effects of the protective colloids of polyvinylalcohol(PVA) and gelatin were investigated through experimentation. The mean size of prepared polyurea microcapsules was smaller and the surface morphology of the microcapsule prepared by the PVA as protective colloid was much smoother than the gelatin. As the concentration of protective colloid increased, the wall membrane of the polyurea microcapsules became more stable, the thermal stability of the wall membrane increased, the mean particle size became smaller, and the particle distribution was more uniform. PET containg microTCPs have a higher activation energy of decomposition, higher char content and lower heat of combustion.

• Textile Coloration and Finishing
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• v.19 no.5
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• pp.30-36
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• 2007

Cypermethrin-containing polyurea microcapsules were prepared by interfacial polymerization using aromatic 2,4-toluene diisocyanate(TDI) and Ethylene diamine(EDA) as wall forming materials. The effects of the protective colloids of polyvinylalcohol(PVA) and gelatin were investigated through experimentation. The mean size of the polyurea microcapsules was smaller and the surface morphology of the PVA was much smoother than gelatin. In addition the release behavior was much more controlled and better sustained. As the concentration of protective colloid increased, the wall membrane of the polyurea microcapsules became more stable, the thermal stability of the wall membrane increased, the mean particle size became smaller, and the particle distribution was more uniform. The release behavior of the core material changed according to the concentration. As the gelatin concentration was increased, a more controlled and sustained release behavior was observed. However, in the case of PVA, the increase of PVA concentration lead to a more rapid release rate.

• Journal of the Korea Institute of Building Construction
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• v.13 no.5
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• pp.465-473
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• 2013

Concrete is an outstanding material in terms of its impact and blast resistance performance. However, there a limitation of concrete is its risk of collapse due to the brittle failure and spalling. Increasing the thickness of members was used as a method to enhance the protective performance of concrete, despite the resulting inefficient space. To solve this problem, different types of fiber reinforced concrete were developed. Recently, another type of fiber reinforced concrete is also being developed and applied as a material that offers protection against impacts and blasts by increasing the flexural toughness of concrete. In this study, the test was conducted to evaluate the impact resistance performance of fiber reinforced concrete and mortar according to impact of high-velocity projectile. A concrete T-wall was also tested to evaluate its protective performance from fragment by 155mm-thick artillery shell. The test results revealed that improving flexural strength through fiber reinforcement inhibited cracks and spalling of rear, and spalling of front by high-velocity impact. As such, it is expected to improve the protective performance of the T-wall and reduce the thickness of the member.

• YAKHAK HOEJI
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• v.52 no.6
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• pp.494-499
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• 2008

The role of antibody in the fungal infections is controversial. However, our previous reports showed a certain epitope in Candida albicans cell wall (CACW) induces protective antibody. A major problem is that the epitope isolation requires tremendous time with high cost. This aspect led us to investigate a simple way inducing protective antibodies against C. albicans. In the present study, we determined if $18{\beta}$-glycyrrhetinic acid ($18{\beta}$-GA) from Glabrae Radix (a family of Leguminosae) has immunoadjuvant activity. Data displayed that the $18{\beta}$-GA suppressed proliferations of both T- and Blymphocytes at high concentrations, whereas below 20 ${\mu}M$ concentration the compound supported the proliferations. These observations indicate that $18{\beta}$-GA has immunoregulatory activity. Based on this observation, an immunoadjuvant effect was examined at the low concentration. Results from animal experiments showed that CACW combined with or without $18{\beta}$-GA produced the anti-C. albicans antiserum in mice. Nevertheless, the CACW combined with $18{\beta}$-GA formula only protected mice against disseminated candidiasis (P<0.05). These data implicate that $18{\beta}$-GA has immunoadjuvant activity, which may provoke the CACW antigen to induce protective antibody. Currently, we are investigating possible mechanism of how the $18{\beta}$-GA provokes such protective immunity against the disseminated disease.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.11a
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• pp.275-276
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• 2023

This study introduces the current progress of study on the development of protective wall aimed at preventing the spread of ultra-fast fires and ensuring fire safety in industrial facilities.

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.4
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• pp.493-500
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• 2013

In this study, it was evaluated the protective performance of the protection material for filed of the army by impact of fragment from the explosion of 155mm artillery shell to propose the improvement items. And it was evaluated the protection materials for structural boby such as corrugated steel plate, concrete block, prevention paint of explosion, aluminum foam and concrete T-wall by impact of fragment of 155mm artillery shells and explosion-induced pressure of C-4 explosive. As a result, protective performance of the existing protective material was superior but reinforcement is necessary for secondary damage because sand is leaking. The protective performance of new protective materials was greater than existing protective materials. And it can be used for protective materials.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.6
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• pp.573-582
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• 2021

In this study, a series of processes for evaluating the effective protection against barriers that should be equipped in institutions that perform reliability tests on high-risk ammunition, such as high-explosive ammunition, were introduced. The impact that high-explosive bombs can have on personnel includes damage to the eardrum and lungs caused by explosion overpressure and penetrating wounds that can be received by fragments generated simultaneously with the explosion. Therefore, a high-explosive with COMP B explosives as its contents were set up, and an explosion protection theory investigation to calculate the degree of damage, numerical calculations and simulations were performed to verify the protection power. A numerical calculation revealed the maximum explosion overpressure on the protective wall when the high-explosive exploded and the penetration force of the fragment against a 50 mm-thick protective wall to be 77.74 kPa and 41.34 mm, respectively. In the simulation verification using AUTODYN, the maximum explosion overpressures affecting the firewall and personnel were 56.68 kPa and 18.175 kPa, respectively, and the penetration of fragments was 35.56 mm. This figure is lower than the human damage limit, and it was judged that the protective power of the barrier would be effective.

• Corrosion Science and Technology
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• v.7 no.5
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• pp.265-268
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• 2008

Prestressed Concrete Cylinder Pipe(PCCP) had became one of the dominating kinds of pipes substituting for steel pipes because of its unique feature (high intensity, high pressure and high leakproofness). PCCP was produced firstly by Bonna company in France. By the end of 20th century, there were over 19000 km of this product installed in America. PCCP was introduced from Ameron company by Shandong Eletric Power Pipeline Engineering Company in 1988. As the statistical data in 2002, 700 km of PCCP had been applied in China, and the application trended towards rapid increase.Since prestressing wire would be corroded in environment, Several accidents due to the breakdown of pipe had happened. Consequently the external wall of pipe should be covered with protective coatings. There was a lack of technical study in corrosion and control of PCCP, because PCCP had been applied for a short time in China. in order to ensure the service life of PCCP, we have developed a kind of protective coating for concrete pipe, which had high intensity and anti-corrosive property with convenient applicability. The physical and chemical properties, painting technology and field application of this coating was introduced in the paper, at the same time, the future of external protective coating for PCCP was looked into.