• Fire Science and Engineering
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• v.32 no.3
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• pp.14-18
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• 2018

The earlier studies on the fire resistance performance of woods used as building materials have focused on confirming combustion characteristics of fire retardant or flame resistant treated wood. In this paper, to confirm internal temperature changes closely related to pyrolysis of woods exposed to the flame, heating experiments were conducted in a heating furnace according to the standard heating temperature curves after Douglas-fir, which is widely used as structural materials, was treated with a flame resistant solution and flame retardant paint. As a result of the experiment, it was confirmed that the thermal diffusion inside the wood has decreased when the wood was treated with the flame resistant solution. However, in high temperature, the flame resistant effect could not be expected due to the peeling of the coating in the case of the flame resistant paint treated wood. Therefore, it can be considered that it is more effective to use the flame resistant solution which penetrates in to the inside of the wood than flame resistant paint which forms the coating on the surface of the wood in order to enhance the flame resistance effect on the thick wood.

• Structural Engineering and Mechanics
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• v.71 no.4
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• pp.417-432
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• 2019

Seismic performance analysis of steel-brace reinforced concrete (RC) frame using topology optimization in highly seismic region was discussed in this research. Topology optimization based on truss-like material model was used, which was to minimum volume in full-stress method. Optimized bracing systems of low-rise, mid-rise and high-rise RC frames were established, and optimized bracing systems of substructure were also gained under different constraint conditions. Thereafter, different structure models based on optimized bracing systems were proposed and applied. Last, structural strength, structural stiffness, structural ductility, collapse resistant capacity, collapse probability and demolition probability were studied. Moreover, the brace buckling was discussed. The results show that bracing system of RC frame could be derived using topology optimization, and bracing system based on truss-like model could help to resolve numerical instabilities. Bracing system of topology optimization was more effective to enhance structural stiffness and strength, especially in mid-rise and high-rise frames. Moreover, bracing system of topology optimization contributes to increase collapse resistant capacity, as well as reduces collapse probability and accumulated demolition probability. However, brace buckling might weaken beneficial effects.

• Fire Science and Engineering
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• v.25 no.2
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• pp.33-38
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• 2011

This study is a research for analysis the states of flame resistant treatment and its system which important in fire prevention by ignition delay of early stage of fire. Some problems arose in the flame resistant treatment site were analysed through the meeting with fire officer and businessman related with flame resistant treatment, and visiting the flame resistant treatment places. From the meeting, visiting and reviewing the code system we find the following problems. First one is a problem of excessive competition with many company in small market of flame resistant treatment and to reduce the cost, the businessman who have no professional technic do not work along the specification. Second one is the inspection system which do not inspect on site but inspect by sampling the flame resistant treated materials submitted by businessman. And there are some problems arose about the reliability and consistency of flame resistant performance of the sample and the treated site. To solve the above problems, we suggest some countermeasure.

• Journal of Biosystems Engineering
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• v.39 no.4
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• pp.299-303
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• 2014

Purpose: This study set out to develop a machine for separating shatter-resistant sesame after threshing. Methods: Three grades of sieve and different blower speeds were tested for a separation system that had been designed specifically for shatter-resistant sesame. Performance tests were run to evaluate the sieve and blower systems in terms of the sesame separation and loss ratios. Results: Tests of the first separation stage using the sieve system revealed the optimum sieve perforation size to be 5 mm. Tests of the second separation stage using the blower system identified the optimum blower speed as being 220 rpm. The optimum separation and loss ratios, of 96.5% and 3.5%, respectively, were obtained at a blower speed of 220 rpm. Conclusions: These results will be useful for the design, construction, and operation of threshing harvesters. For shatter-resistant sesame, an optimum blower speed of 220 rpm was identified.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.214-215
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• 2014

Technologies on energy saving and materials used in curtain walls have progressed with increase of high-rise and large buildings. This study is explain fire resistance performance of the curtain walls. And focused on bond strength of light-weight inorganic ceramic board in high temperature for fire resistant curtain-wall system. From the result, curtain-wall system high fire resistant using the light-weight inorganic ceramic board.

• Fibers and Polymers
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• v.2 no.4
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• pp.190-195
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• 2001

Additives, such as sodium perborate and borax, were examined in dialdehyde wrinkle resistant finishing of cotton. Results indicated that the whiteness index(WI) of cotton treated with dialdehyde and additive showed about 90% of WI of the untreated cotton but with decrease in wrinkle recovery angle (WRA) due to inhibition effect of these additives. Effect of additive on the WRA reduction was more prominent with glutaraldehyde than with glyoxal. Reduction in WRA of cotton treated with both dialdehydes and boron compound was minimized by simultaneous addition of formic acid in the bath. Addition of formic acid was also generally beneficial in maintaining WI retentions after 8 months storage. Furthermore, boron compounds were also effective in improving retentions of mechanical properties. By FTIR analysis the residual aldehyde group was detected on the dialdehyde-finished cotton, whereas no peak was shown by addition of boron compounds. This suggested that the residual aldehyde group was a main cause of fabric yellowing on the dialdehyde-finished cotton. Dialhehyde with boron compound, therefore, can be used to replace a conventional formaldehyde-containing wrinkle resistant finishing of cotton.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.5
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• pp.72-81
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• 2018

Fireproof structures using concrete, built-up panels and dry walls are usually used in walls inside fire compartments. However, demand for glass walls is emerging due to increase in interest in visibility and external appearance. In this study on steel fire resistance walls using insulation glass, fire resistance tests and performance evaluations were conducted on 60 minute fire resistance walls and exterior walls which could be applied to interior fire compartments and 90 minute fire resistance walls which could be applied to curtain walls. According to the tests, the specimens satisfied the required fire resistance performance. The finite element analysis was conducted after the tests to evaluate the fire resistance performance of the glass walls. The analysis results showed that the preliminary evaluation of fire resistance performance would be feasible.

• Fire Science and Engineering
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• v.30 no.3
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• pp.7-15
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• 2016

The cross-sectional shape factor is used worldwide to evaluate the scientific performance of fire-resistant structures. In South Korea, however, a system for applying a cross-sectional shape factor has not been arranged and circular or rectangular steel pipes are commonly used for large-scale steel frame buildings. On the other hand, coating material-spray steel beams and pillars that have received the certification of a fire-resistant structure from recognized organizations are mostly limited to a H-beam. A H-beam is granted a wide range of certifications without size limitations from a non-loading performance test with test standards based on the relevant provisions. Other types of steel pipe are to be certified for fireresistance according to shape. In this study, a cross-sectional shape factor was used to propose standard testing specifications for the application of coating material-sprayed circular and rectangular steel pipes, eventually to set the scope of certification for reasonable fire-resistant structures.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.4
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• pp.83-90
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• 2018

Considering the increased threats from worldwide terrors and the increased demands on the blast resistant design of commercial buildings, this study is aimed at understanding the basic concept of blast resistant design and evaluating the blast performance with an actual design example. Although there are many differences between earthquake and blast loads, the design concept against both loads is similar in terms of allowing the plastic behavior of a structure and sharing the ductile detailing. Through the blast performance evaluation of a target building provided in this study, it is noted that a well-designed building for the conventional loads can have a certain level of blast resistance. However, this cannot be generalized since the blast load on a structure varies depending on the type of weapon, TNT equivalence, standoff distance, etc. Architectural planning with positioning the sacrificial structure or maintaining a sufficient standoff distance from the expected detonation is the simple and effective way of improving the blast resistance of a building.

• Journal of Digital Convergence
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• v.19 no.4
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• pp.159-166
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• 2021

This study was an attempt to develop a multidrug resistant organisms infection control simulation program for nurses at small and medium sized hospitals and to evaluate the effectiveness of said simulation program. This is a single-group, pre-post experimental design study conducted on 33 nurses working at small and medium sized hospitals. Data obtained were analyzed using the IBM SPSS 21.0 program, along with the use of descriptive statistics and paired t-test. Regarding the results of the study, multdrug resistant organisms infecion control knowledge(t=-10.764, p<.001)and performance levels(t=-4.215, p<.001) of the nurses displayed statistically significant increases following application of the simulation program. There is a need for the development of more diversified simulation programs in the future since the improvement in the infection control knowledge and performance levels of nurses is important to block the spread of multidrug resistant organisms and prevent infection outbreak thereof with medical institutions.