Fire Spread in Insulation Materials in the Ceiling of a Piloti-Type Structure

In piloti-type structures, large-scale fires frequently occur because insulation materials in the ceiling are ignited. However, the spread of fire in these cases is not well known. Therefore, this study conducted small-scale (1.0 m × 1.0 m) tests and real-scale model tests. According to the results, we clarified the fire spread, temperature variation over time, and the effects of insulation materials in fire sites. For the small-scale tests, the internal structure of the ceiling was extruded polystyrene (XPS) + sheet molding compound (SMC), retardant expanded polystyrene (Retardant EPS) + sheet molding compound (SMC), and extruded polystyrene (XPS) + design metal ceiling (DMC). From the small-scale and large-scale tests that simulated a fire in a piloti-type structure, the flow of heat in the interior space and the cause of a large fire were identified. The tests were conducted with EPS+DMC, defined as the best-case scenario, and XPS+SMC, defined as the worst-case scenario during a fire accident. The results from the tests showed that combustion began when the insulation material was exposed to the fire source. Then, molten XPS fell onto the SMC, establishing a new fire source that destroyed the ceiling material, leading to increased combustion due to the inflow of oxygen.

A Study on the Relationship between Firefighters Disease and Health Status

Considering the age and longer service time of firefighters who have a substantial amount of field activities, they are exposed to chemical and biological risk factors, physical and mental stress, diverse and complex work environments, and repetitive motions, which may increase the rates of gastrointestinal disorders, musculoskeletal diseases, cancers, and cardiovascular diseases. Therefore, based on the regular specific health examination results for 215 firefighters who were working in the N fire department located in B metropolitan city, an analysis of occupational diseases was performed, which showed that the most common chronic disease was diabetes mellitus (28.8%), followed by hyperlipidemia (27.9%) and thoracic diseases (19.5%). This trend appears to be consistent with the incidence rates reported in a representative study of adult diseases in Korea. In addition, it was found that 82 officers maintained healthy states, while those who needed further medical inspection and those with clinical symptoms were more frequently exposed to disease when they were older and had longer service time; moreover, the fire captain and lieutenant had higher rates of disease.

Proposal of Air Supply Smoke Control System about Stair-case Considering Stack Effect & Opening of the Outside Door

Most of the special escape staircase smoke control systems for high-rise buildings in accordance with the national fire safety code NFSC 501A are constructed with smoke control only vestibule, making it difficult to expect a proper role in an emergency. This standard, which was created by introducing the concept of air supply pressurized smoke control 25 years ago, created Korea´s smoke control only vestibule, which was not found in developed countries, and has been mainly applied to it to fit into the poor architectural environment of the time. However, there is a fundamental flaw there, so the performance test for completion without occupants is passed, but in the presence of occupants, the performance does not come out properly and it is being blamed for being useless. In this regard, the author proposes a method of air supply pressurized smoke control for stair-case that avoid the smoke control method only vestibule, reduces the stack effect with good cost-effectiveness, and considers opening the outside entrance door of the stair-case.

The Effects of the Working Environment of Firefighters on the Quality of Life

This study aimed to contribute to the preparation of an action plan for the improvement of the quality of life of firefighters at the individual level by examining how the working environment as perceived by firefighters affects their quality of life. To this end, this study conducted a survey that used purposive sampling targeting 201 fire-fighting officers in Incheon. The survey results showed that of the sub-variables of the working environment of firefighters, monetary rewards, challenges, and promotion had a significant influence on the quality of life. Based on the results, this study suggested various action plans that can support the working environment and improve the quality of life of firefighters.

Development of an ABS Nanocomposite Material and Its Application to a Fire-Resistant Glazing System - Part I: Development of an ABS Nanocomposite Material

This study is focused on the development of a curtain-wall-type fire-resistant glazing system to contribute to both energy efficiency and fire safety of a building. The weakness of the aluminum frame on thermal insulation was supplemented by an ABS nanocomposite material with a superior thermal insulation performance. It contained (i) a maleic-anhydride-grafted ABS to improve the dispersion of clay, (ii) nanoscale clay, and (iii) intumescent material to retard the combustion on the exposed surface of the polymer. A series of X-ray diffraction, transmission electron microscopy, differential scanning calorimetry, LFA, and cone calorimetry tests were carried out to analyze the degree of improvement in flame retardancy and optimize the compound ratio. In Part II (the authors’ companion paper), the ABS nanocomposite material based on the optimized compound ratio was scaled up for application to a fire-resistant glazing system in industries. Bench- and full-scale tests were performed to confirm the system’s performances in terms of both thermal resistance and insulation.

Exploratory Study on Trauma Scoring Systems for SAVE Triage

This study examined several trauma scoring systems that serve as the basis for applying the Secondary Assessment of Victim Endpoint (SAVE) severity classification to propose a method that can be applied during triage. By using an exploratory method, data collected from different trauma scoring systems was qualitatively evaluated. First, it was confirmed that the survival risk ratio (SRR) of the International Classification of Disease-based Injury Severity Score (ICISS) can be used for SAVE severity classification. Second, the Korean Trauma Data Bank (KTDB) of the Central Emergency Medical Center does not indicate the SRR of each injury according to the Korean standard classification of disease and cause of death (KCD). Third, the SRR of injuries, from data acquired from the United States can be used for classification of SAVE severity classification. Fourth, the addition of SRR from the KCD to the KTDB can be used for SAVE severity classification.

Analysis of the Effectiveness of Fire Drone Missions at Disaster Sites: An Empirical Approach

The use of drones in the public sector is expanding to various fields, and its effectiveness has been verified in some cases. Since its introduction to the Seoul Metropolitan Fire and Disaster Headquarters in 2016, drones have been used 1,240 times, including 405 times in disaster response. The purpose of this study is to analyze cases to determine the effectiveness of drones in operations such as searching, acquiring information, and monitoring, compared to traditional disaster response methods. In order to analyze the efficiency of the search missions, we divided the cases into vertical and horizontal searches and measured the response time of the drone compared to that of the firefighters. In terms of the information acquisition missions, the time spent on obtaining information and responding activities when the drone was deployed at building and forest fire sites were compared to missions in which the drone was not deployed. In the case of risk monitoring missions, the scope of the safety management personnel usually deployed at the site and the scope of the drone monitoring were compared. In horizontal searches, such as searching for missing persons, one drone can play the role of 100 people. In addition, drones are more than sixteen times faster than traditional methods in completing vertical searches in high-rise buildings, and 140 s faster in detecting fires in residential areas. Furthermore, it took more than an hour for 78 firefighters to locate a forest fire that broke out at night, but the drone located it in just two min. These results indicate that it is possible to use firefighter personnel more effectively and efficiently by using drones at disaster sites. To that end, more research on how to modulate the duties of firefighters while working with fire drones is required.

Diagnosis of Abnormal Heat Generation in the Connection Part in Low Voltage MCCBs for Fire Risk Prediction

This study is conducted to determine the critical temperature under normal current flow by estimating normal heat generation; the saturation temperature of the connecting part of a circuit breaker is simultaneously measured by sub-dividing the rated current of molded case circuit breaker (MCCB) into 10 steps. Further, a risk analysis was conducted via an investigation of thermal characteristics. To this end, five types of MCCBs were selected while building a temperature test box; further, the heat generation temperature of the three phases on the line and load sides was measured using the sub-divided load current to represent the electrical heat variation and a high-current-generating tester real-time. The results the test, demonstrate that the temperature of the connecting part of the MCCB stably increased; in addition, the standard of the heat generation could be established and the load amount could be predicted by measuring the temperature variation. Meanwhile, the heat generation temperature was different for different types of wirings such as power lines and Busbar. Further among the R, S, and T phases of the MCCB, S phase temperature was slightly higher than those of the others. This study can serve as a theoretical reference for future applied research on the dangers of fire due to the heat generation of the connecting part of the MCCB, wherein the risks of abnormal heat generation need to be analyzed. The results obtained can be applied not only to prevent the carbonization accidents of MCCBs installed inside distribution panels being used at industrial sites, but also to manage the risks of the distribution circuit breaker and prevent the electrical fire.

Moderating Effect of Vocational Calling on Firefighters’ Stress and Burnout

Firefighters are exposed to complex stresses resulting from life-threatening risks in the work environment, expanding scope of work, insufficient compensation and support. This study investigated the role of vocational calling in job stress leading to burnout, which impairs mental health and organizational effectiveness. One hundred and ninety-one firefighters (average age, 40.97 years; average career, 13.14 years) participated in the study. Firefighters with a high sense of calling showed lower burnout at both low and high stresses than those with a low sense of calling. In the group with low sense of calling, burnout increased more rapidly as the stress level increased than in the group with high sense of calling. As a psychological resource, sense of calling, which leads to the perception of one’s work as meaningful and purposeful, showed a moderating effect that buffers the effect of stress on burnout.

Effect of the Cone Heater Scale Compliant with the ISO 5660 Standard on Spatial Uniformity of Radiant Heat Flux

Physical quantities such as mass loss rate, heat release rate, and total heat release are often measured through a cone calorimeter (a representative bench-scale apparatus) and are primarily considered as values per unit area. Hence, the uniformity of radiant heat flux supplied by the cone heater to the specimen is very important with respect to the measurement results’ validity. In this study, on the basis of the ISO 5660 standard, the uniformity of radiant heat flux at the specimen surface was evaluated for the cone heaters used with the cone calorimeter. It is observed that a normal cone heater (NCH) compliant with the ISO 5660-1 standard satisfies the requirement of uniformity within a range of ± 2% in the central 5 cm × 5 cm area, but it has a large deviation of approximately 13% at the position corresponding to the edge of the specimen. In addition, the duration of NCH usage does not significantly affect the distribution of radiant heat flux. Furthermore, it is observed that a large cone heater compliant with the ISO/TC 5660-4 standard can supply moderately-uniform radiant heat flux over the entire surface area (10 cm × 10 cm) of the specimen.