• Journal of the Korea Concrete Institute
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• v.23 no.6
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• pp.749-756
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• 2011

Most experimental studies on durability of FRP reinforcements subjected to high temperature have focused on the effect of high temperature only on tensile properties. But FRP reinforcement used in newly constructed concrete structure is first degraded by moisture and alkaline environment of concrete. When the structure is subjected to fire, the degraded FRP reinforcement is exposed to high temperature. Therefore, the effects of concrete environment and high temperature should be simultaneously considered for evaluation of FRP reinforcement damaged by fire. In this study, FRP reinforcements submerged in simulated solutions of pH 12.3 and 7 for extended period of time were subjected to temperatures of $60^{\circ}C$, $100^{\circ}C$, $150^{\circ}C$, and $300^{\circ}C$ to be examined. In order to investigate the effect of the high temperature, interlaminar shear strengths were measured and compared to those of control ones. The experimental results demonstrated that the combined effect of concrete environment and high temperature on properties of FRP reinforcement was more significant than the effect of high temperature or concrete environment solely.

• International Journal of Concrete Structures and Materials
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• v.11 no.1
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• pp.17-28
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• 2017

Although concrete is a noncombustible material, high temperatures such as those experienced during a fire have a negative effect on the mechanical properties. This paper studies the effect of elevated temperatures on the mechanical properties of limestone, quartzite and granite concrete. Samples from three different concrete mixes with limestone, quartzite and granite coarse aggregates were prepared. The test samples were subjected to temperatures ranging from 25 to $650^{\circ}C$ for a duration of 2 h. Mechanical properties of concrete including the compressive and tensile strength, modulus of elasticity, and ultimate strain in compression were obtained. Effects of temperature on resistance to degradation, thermal expansion and phase compositions of the aggregates were investigated. The results indicated that the mechanical properties of concrete are largely affected from elevated temperatures and the type of coarse aggregate used. The compressive and split tensile strength, and modulus of elasticity decreased with increasing temperature, while the ultimate strain in compression increased. Concrete made of granite coarse aggregate showed higher mechanical properties at all temperatures, followed by quartzite and limestone concretes. In addition to decomposition of cement paste, the imparity in thermal expansion behavior between cement paste and aggregates, and degradation and phase decomposition (and/or transition) of aggregates under high temperature were considered as main factors impacting the mechanical properties of concrete. The novelty of this research stems from the fact that three different aggregate types are comparatively evaluated, mechanisms are systemically analyzed, and empirical relationships are established to predict the residual compressive and tensile strength, elastic modulus, and ultimate compressive strain for concretes subjected to high temperatures.

• Fire Science and Engineering
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• v.34 no.3
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• pp.126-133
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• 2020

The purpose of this study was to investigate the effects of unconditional self-acceptance and self-exposure of trainees on the post-traumatic growth and to develop a program to achieve post-traumatic growth beyond the previous level without suffering from psychopathological consequences such as post-traumatic stress disorder I wanted to help. For this purpose, unconditional self-acceptance, self-exposure, and Korean post-traumatic growth scale were used. First, it was confirmed that unconditional self-acceptance and self-exposure of firefighters are correlated with post-traumatic growth. Second, hierarchical regression analysis showed that unconditional self-acceptance has more influence on self-acceptance and post-traumatic growth than self-acceptance of firefighters. Based on the results of this study, we propose the program development and therapeutic intervention strategies to promote post-traumatic growth of firefighters.

• Fire Science and Engineering
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• v.34 no.3
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• pp.28-34
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• 2020

In this study, an ISO 5660-1 cone calorimeter experiment was conducted to examine the effects of changes in flow and thermal thickness around solid combustibles on heat release rate characteristics. Polymethyl methacrylate (PMMA) is a solid combustible material that does not generate char during the combustion reaction. Hence, it was selected for the experiment, and the thermal penetration depth was calculated to distinguish the thermal thickness of PMMA. Furthermore, the thermal decomposition characteristics were analyzed by measuring the heat release rate measured during the combustion of PMMA. This was performed after generating the forced flow around the combustibles by setting the duct flow of the cone calorimeter to 12, 24, and 40 L/s. The results confirmed that the thermal release rate of the thermally thin combustible material was not significantly affected by the change in the surrounding flow. Hence, the thermally thick combustible material was significantly affected by the change in the flow rate.

• Fire Science and Engineering
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• v.23 no.6
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• pp.16-23
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• 2009

The performance characteristics of a smoke damper, which aims to suppress the penetration of smoke to a safe area, have been tested under the regulation of the FIS 001. However, the improvement of the test methods and the regulation has consecutively been requested. From a view-point of fluid mechanical theory, a pressure control damper, that is installed at the end of the flow control system, is important and it dominates flow characteristics in all designed flow systems. In this study, the weak points of the regulation of the FIS 001 concerned with the pressure control damper was visited and the some important characteristics of the damper was examined. Based on these results, it was confirmed that the effects of flow disturbance in the air supplying duct on the performance of the damper are not significant. This results gives some information for the modification of the experimental regulation concerned to the pressure control damper.

• Fire Science and Engineering
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• v.33 no.2
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• pp.20-29
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• 2019

In this paper, the effect of spontaneous combustion inhibitor on the surface of coal stockpile in coal yard was investigated by numerical analysis. First, the numerical analysis method of the present study was compared with the results of the previous study by analyzing the case where the spontaneous combustion inhibitor was not applied, and the effect of preventing spontaneous combustion by various areas and positions for spraying spontaneous combustion inhibitor was analyzed. As a result, the larger the application area of the spontaneous combustion inhibitor, the more the effect of preventing spontaneous combustion by blocking the oxygen inflow into the coal stockpile, and the greater the effect of the spontaneous combustion prevention when spraying spontaneous combustion inhibitor from the bottom of the coal stockpile. Spontaneous combustion inhibitor should be sprayed effectively, considering the economic aspects, such as manufacturing cost etc.

• The Journal of the Convergence on Culture Technology
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• v.5 no.1
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• pp.185-191
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• 2019

The use of smartphone improves convenience and efficiency in modern people's lives but threatens the mental health of individuals by manifesting an addiction phenomenon that is difficult for everyday life without a smartphone. In particular, it is suggested that the effects of the smartphone addiction of firefighters who have a high level of job stress due to work environment exposed to disaster and fire have a very negative effect on their personal well-being and job performance. Therefore, the analysis of the relationship between firefighters' smartphone addiction and stress will be helpful in examining the problems of stress management. This study analyzed the relationship and influence between smartphone addiction and stress of firefighters. Total study subjects were 230 and SPSS 20.0 was used. Statistical methods are group analysis (t-test and ANOVA) and multiple regression analysis. The results of this study show that firefighters' household type and monthly income have a significant effect on stress. Of the sub-factors of smartphone addiction, withdrawal experience has a statistically significant effect on stress. The results of the study will provide empirical data on the smartphone addiction of fire service employees.

• Journal of People, Plants, and Environment
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• v.24 no.2
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• pp.137-152
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• 2021

Background and objective: This study was carried out to investigate and analyze the preference for plant fragrance and the psychological effects of a agro-healing activity in 101 firefighters aged 39.71 ± 10.94. Methods: For the psychological evaluation, post-traumatic stress symptoms, Korean occupational stress scale short form (KOSS-SF), emotional intelligence, and job satisfaction were surveyed on the Likert scale. For the preference for plant fragrances, 20 ㎕ of commercially available essential oils from four plant species (Mentha spp., Lavandula spp., Citrus limon, C. sinensis) were absorbed into each test paper and provided to the participants. Results: The rate of post-traumatic stress symptoms was high at 37.6% of the firefighters surveyed.. C. limon fragrance had the highest preference among the four plant fragrances, followed by C. sinensis > Mentha spp. > Lavandula spp. with statistically significant difference (F = 14.256, p < .001). The lower their age, income, and position, and higher the education level, the higher the preference for plant fragrances. And the administrative group had higher preference for plant fragrances than field group. In addition, as a result of examining the correlation between job satisfaction, preference for plant fragrance, post-traumatic stress, emotional intelligence, and job stress for fire-fighters, the higher the job satisfaction, the higher the fragrance preference and emotional intelligence, and the lower the post-traumatic stress and job stress. Conclusion: Therefore, installing a garden using botanical fragrances at workplaces that firefighters can easily access will improve job satisfaction and relieve stress. It can be concluded that applying the fragrance of plants to the healing farming activities at the fire-fighter's workplace can increase the usefulness of the healing activities.

• Journal of the Society of Disaster Information
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• v.18 no.3
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• pp.660-671
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• 2022

Purpose: This study is intended to confirm the business disruptive risk in the Serious Accidents, and propose a plan to comply with the Serious Accidents Punishment Act through the Disaster Mitigation Activity Management System. Method: Through literature review and case studies, the requirements and characteristics of each of the Serious Accidents Punishment Act, the Disaster Mitigation Activity Management System, and ISO 45001 were compared and analyzed, and implications were derived. Result: The business disruption and financial adverse effects caused by industrial accidents were identified. Based on this and by using the Disaster Mitigation Activity Management System, measures to link the documentation requirements of the the Serious Accidents Punishment Act to the Disaster Mitigation Activity Management System, and to manage the implementation records of the Serious Accidents Punishment Act's duty were derived. Conclusion: When establishing and operating the Disaster Mitigation Activity Management System, it can not only comply with the Serious Accidents Punishment Act but also contribute to maintaining business continuity and ESG management through the prevention of various disasters and the minimization of secondary damage, etc.

• Journal of Home Health Care Nursing
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• v.31 no.1
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• pp.16-29
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• 2024

Purpose: This scoping review aimed to synthesize the characteristics and effects of interventions designed to prevent unintentional home injuries in older adults in Korea. Methods: The review was conducted following the Joanna Briggs Institute protocol. A literature search was performed for studies published between 2001 and 2022 in the DBPia, RISS, KMBase, and NDSL databases. A total of 1,620 studies were identified, and 27 studies were included in the final analysis. Data were analyzed for characteristics of the literature, intervention-related unintentional injury mechanisms, and safety areas. Results: Most selected studies utilized a quasi-experimental design and targeted elderly women. In terms of injury mechanisms, 21 of 27 studies focused on falls, 2 on fire/disaster, 3 on drugs, and 1 on food. The most common preventive intervention for falls was exercise, and its effectiveness was verified using physical safety variables. Interventions in the fire/disaster, drug, and food domains were all educational, and changes in knowledge, behavior, and attitude were verified. Conclusion: This study confirmed the effectiveness of interventions for preventing unintentional injuries in the homes of community-dwelling older adults. These findings can serve as a foundation for developing and implementing unintentional injury prevention interventions at home for community-dwelling older adults. Multidisciplinary research is needed to address multifaceted safety issues by considering the home environment and injury risk factors.