• Journal of Korean Living Environment System
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• v.24 no.1
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• pp.95-106
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• 2017

The purpose of this study was to evaluate comfort functions while wearing firefighters' protective gloves in dry and wet conditions at $70^{\circ}C$ air temperature with radiant heat. Four types of firefighting gloves from Korea, Germany, United States, and Japan were evaluated in both dry and wet conditions by eight male firefighters. Firefighters put their hands and forearms wearing gloves into a hands-radiant chamber that maintained at an air temperature of $70{\pm}2^{\circ}C$ ($T_a$) and globe temperature $106^{\circ}C$ ($T_g$). During the exposure, subjects followed a fixed protocol of manual movements and stopped the exposure when they felt being intolerable. Results showed that completion time was extended by 6 min on average when gloves got wet and 15 min for the Japanese gloves was extended when compared to its dry condition (p<.001); microclimate humidity on the palm at the last stage was greater for wet conditions than dry conditions in the all gloves; and skin temperatures on mid-fingertip, palm, and hand were significantly lower for wet conditions than dry conditions especially for Japanese gloves (p<.001). These results indicate that the exposure time without thermal pain to radiant heat could be extended by wetting gloves during the low radiant heat exposure.

• Journal of the Korean Society of Clothing and Textiles
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• v.23 no.6
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• pp.853-863
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• 1999

the change of physical properties (thickness, weight, air permeability) and mechanical properties(abrasion resistance breaking load and displacement) of samples were determined after heat exposure by a RPP tester. The effect of exposure time and heat flux intensity on the changes and the relationship between physical properties and mechanical properties were investigated. FR treated cotton Kevlar/PBI and Nomex with different structureal characteristics were chosen for specimens. The changes of physical properties and mechanical properties were calculated based on their initial values before heat exposure. The longer exposure time and the high heat flux intensity the more changes of those properties. Heat flux intensity was more effective on the changes, The showed to be affected by an interplay of shrinkage and pyrolysis products loss. The changes of thickness and abrasion resistance showed to be higher for plain weave fabric and those of air permeabiliyt and breaking load and displacement for twill weave fabric. While FR treated cotton which have high RPP value experienced serious and detrimental changes after heat exposure Kevlar/PBI which has low RPP value showed no high changes. In conclusion it could be confirmed that when total performance of a protective clothing is estimated retention capability of physical and mechanical properties after heat exposure as well as RPP value must be considered.

• Journal of the Korean Society of Safety
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• v.17 no.3
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• pp.56-60
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• 2002

The purpose of this study was to present the thermal characteristics of the working uniform exposed to the radiation heat. The effect of exposure time and exposure distance on the changes and the relationship between physical properties were investigated experimentally. Regardless of the kind of working uniform, the surface temperature of the working uniform with exposed time sharply increases as exposed distance is more close and the reaching time of steady state is shorter. The surface temperature of working uniform exponentially decreases as exposed distance become more distant. For the safety of the working man, it is necessary that he work far away at a fixed standard distance from the radiant heat source.

• Fire Science and Engineering
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• v.28 no.4
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• pp.97-103
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• 2014

To ensure adequate protection from the risk of burns, fire fighter's turnout has a composite of more than three components and air gaps between layers of materials. During the flame exposure, radiation and convection heat transfer occurs in the air gap, thus the air gap acts as a thermal resistance with non-linear characteristics. Therefore, in this study, the experiments were performed to identify the effect of various air gap width (0~7 mm) on the thermal protective performance of fire fighter's clothing. The temperatures on each layer and RPP (Radiant Protective Performance, the most effective index representing the thermal protective performance) were measured with various incident radiant heat fluxes. The temperature at the rear surface of the garment decreased and RPP increased with increasing air gap width because the thermal resistance increased. Especially, it could be found that RPP value and air gap width has almost linear relation for the constant incident heat flux conditions. Thus relatively simple RPP predictive equation was suggested for various incident heat flux and air gap conditions.

• Fire Science and Engineering
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• v.28 no.2
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• pp.1-8
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• 2014

Despite advancements in the development of synthetic fibers and materials that provide better insulation, fire burn injuries remain a significant issue. To ensure adequate protection, clothing and equipment must be selected on the basis of performance. There are different standards like ISO standards applicable to each of the various types of clothing used by fire fighters. But, in most cases, the tests are performed in the conditions of high heat flux exposure, the clothing material can be destroyed easily. Thus the effective way to investigate the protective performance for the low (radiant) heat flux conditions should be needed. Therefore improved RPP (Radiant Protective Performance) test method based on the onset of pain burn injury was suggested. Experiments were performed to verify the proposed method with current protective clothing for fire fighters and the transient heat transfer characteristics were identified, also. Moreover, several protective performance indices were acquired from experimental results to analyze their relations.

• Journal of Mechanical Science and Technology
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• v.15 no.2
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• pp.239-247
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• 2001

Measured radiative heat fluxes on the furnace exit plane of a heavy duty power boiler of steam output 1650 T/h are discussed. A high-ash pulverized bituminous coal was used. Such measurements are necessary to improve heat fluxes inside a steam boiler furnace was manufactured. An extra small heat radiation sensor was placed in the water cooled head of the probe. The sensor had no direct contact with furnace gases and measured only the radiant energy. There was no exposure to convective heat transfer. With the radiometric probe, one can obtain a spherical indicatrix of radiation intensity as well as hemispherical radiative heat flux incident on any surface passing through a measuring point inside the furnace. Thus, the quantity of radiation energy, passing through the furnace exit plane, to the convective heating surfaces and the quantity of radiation energy going in the opposite direction were measured. A formula for relative radiative heat flux on the furnace exit plane has been proposed.

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.2
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• pp.197-203
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• 2014

In this paper, the effect of unsteady radiation on the horizontal fin of an external fuel tank by flame of a flying flare was analysed to see the temperature increase of the fin and the thermal impact on the fin. Radiation between two surfaces was calculated using the concept of radiation resistance of surface and space including radiation, irradiation and shape factor for two flying trajectories of a flare, maximum temperature of 2200 K, emissivity of 0.95, flying velocity of 30 m/s, and thermal surface area of $0.01m^2$. The result shows that the temperature increase of the fin is 0.236 K, and the thermal effect on the fin is ignorable. And it was found that temperature is increased a little because small amount of heat energy can be radiated due to the short exposure time to the heat source.

• International Journal of High-Rise Buildings
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• v.7 no.4
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• pp.299-311
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• 2018

As engineered timber such as Glulam is seeing increasing use in tall timber buildings, building codes are adapting to allow for this. In order for this material to be used confidently and safely in one of these applications, there is a need to understand the effects that fire can have on an engineered timber structural member. The post-fire resilience aspect of glulam is studied herein. Two sets of experiments are performed to consider the validity of zero strength guidance with respect to short duration fire exposure on thin glulam members. Small scale samples were heated in a cone calorimeter to different fire severities. These samples illustrated significant strength loss but high variability despite controlled quantification of char layers. Large scale samples were heated locally using a controlled fuel fire in shear and moment locations along the length of the beam respectively. Additionally, reduced cross section samples were created by mechanically carving a way an area of cross section equal to the area lost to char on the heated beams. All of the samples were then loaded to failure in four-point (laterally restrained) bending tests. The beams that have been burnt in the shear region were observed as having a reduction in strength of up to 34.5% from the control beams. These test samples displayed relatively little variability, apart from beams that displayed material defects. The suite of testing indicated that zero strength guidance may be under conservative and may require increasing from 7 mm up to as much as 23 mm.

• International Journal of Advanced Culture Technology
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• v.11 no.3
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• pp.346-357
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• 2023

The purpose of this study is to suggest improvement plans for prevention regulations by reflecting the toxicity, fire and explosion effects of hazardous materials factories and surrounding areas using an off-site consequence assessment program. Regarding the effects of the hydrogen cyanide leak accident, which is the 1st petroleum of the 4th class flammable liquid, Areal Locations of Hazardous Atmospheres (ALOHA) program was used to compare and analyze the extent of damage effects for toxicity, overpressure, and radiation. As a result, the toxicity was analyzed to exceed 5km in the area with Acute exposure guideline level (AEGL)-2 concentration or higher, the overpressure was 103m in the range of 1 psi or more, and the radiant heat was analyzed to be 724m in the range of 2kw/m² or more. Toxicity and radiation affected the area outside the hazardous material storage area, but the overpressure was limited to the inside of the hazardous material storage area. Therefore, we propose to improve the safety management of hazardous materials by conducting a risk assessment for hazardous materials and reflecting the results in internal and external emergency response plans to prepare prevention regulations.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.26 no.1
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• pp.47-59
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• 2023

Due to climate change and urbanization, abnormally high temperatures and heat waves are expected to increase in urban and deteriorate thermal comfort. Planting of street trees and changing the albedo of urban surfaces are the strategies for mitigating the thermal environment of urban, and both of these strategies affect the exposure and blocking of radiative fluxes to pedestrians. After measuring the shortwave and longwave radiation according to the ground surface with different albedo and the presence of street trees using the CNR4 net radiometer, this study analyzed the relationship between this two strategies in terms of thermal environment mitigation by calculating the MRT(Mean Radiant Temperature) of each environment. As a result of comparing the difference between the downward shortwave radiation measured under the right tree and at the control, the shortwave radiation blocking effect of the tree increased as the downward shortwave radiation increased. During daytime hours (from 11 am to 3 pm), the MRT difference caused by the albedo difference(The albedo of the surfaces are 0.479 and 0.131, respectively.) on surfaces with no tree is approximately 3.58℃. When tree is present, the MRT difference caused by the albedo difference is approximately 0.49℃. In addition, in the case of the light-colored ground surface with high albedo, the surface temperature was low and the range of temperature change was lower than the surrounding surface with low albedo. This result shows that the urban thermal environment can be midigate through the planting of street trees, and that the ground surface with high albedo can be considered for short pedestrians. These results can be utilized in planning street and open space in urban by choosing surfaces with high albedo along with the shading effect of vegetation, considering the use by various users.