• Fire Science and Engineering
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• v.28 no.1
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• pp.44-51
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• 2014

Smoke from fire is a mixture of combustion gases and particles which include micro-droplets formed from condensed organic vapors and carbonaceous agglomerates. The inhalation of smoke particles causes adverse health effects, and it is prerequisite for the hazard and risk analysis of the smoke particles to know how they behaviour in the respiratory tract. The characteristics of the absorption and adsorption of toxic gases and the amount and location of the particle deposition within the respiratory tract that determine the adverse health effects are related to the morphology and the size distribution of smoke particles. In the present work, as a preliminary study for the adverse health effects of smoke particles, the morphologies of the smoke particles from combustible materials were investigated for each fire stage: smouldering, well-ventilated flaming, small under-ventilated flaming, fully-developed under-ventilated fire. The steady-state tube furnace method given in ISO/TS 19700 was used for the generation of smoke particles. The fire stages were controlled by changing furnace temperature and equivalent ratio. The morphologies were analyzed by using Transmission Electron Microscope (Bio-TEM) by collecting the particles on TEM grids put on each stage of a cascade impactor.

• Journal of the Korean Society of Tobacco Science
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• v.12 no.1
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• pp.19-27
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• 1990

To evaluate tobacco quality, several mathods including sensory test, or measurement of some toxic compounds such as tar, nicotine and carbon monoxide in cigarette smoke have been used. However, many detrimental effects of smoking on the physiological functions including respiratory system reported were turned out to be the action of reactive oxygen species. Therefore, the amounts of oxygen free radicals such as superoxide, hydroxyl radical, even hydrogen peroxide in the cigarette smoke are thought the very important factors. In the present study, we have determined the generation of superoxide and the content of hydrogen peroxide using superoxide dismutase and catalase in the gas and particulate phases obtained from cigarette smoke, respectively. In the aqueous extracts of total particulate materials, suproxide and hydrogen peroxide were detected, and there was an excellent correlation between oxygen tint of oxygen free radicals in cigarette smoke may be a useful index for evaluation of cigarette quality in the aspect of smoking and health.

• The Korean Journal of Physiology and Pharmacology
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• v.15 no.6
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• pp.397-403
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• 2011

The proliferation, migration, cytokine release, and contraction of airway smooth muscle cells are key events in the airway remodeling process that occur in lung disease such as asthma, chronic obstruction pulmonary disease, and cancer. These events can be modulated by a number of factors, including cigarette smoke extract (CSE). CSE-induced alterations in the viability, migration, and contractile abilities of normal human airway cells remain unclear. This study investigated the effect of CSE on cell viability, migration, tumor necrosis factor (TNF)-${\alpha}$ secretion, and contraction in normal human bronchial smooth muscle cells (HBSMCs). Treatment of HBSMCs with 10% CSE induced cell death, and the death was accompanied by the generation of reactive oxygen species (ROS). CSE-induced cell death was reduced by N-acetyl-l-cysteine (NAC), an ROS scavenger. In addition, CSE reduced the migration ability of HBSMCs by 75%. The combination of NAC with CSE blocked the CSE-induced reduction of cell migration. However, CSE had no effect on TNF-${\alpha}$ secretion and NF-${\kappa}B$ activation. CSE induced an increase in intracellular $Ca^{2+}$ concentration in 64% of HBSMCs. CSE reduced the contractile ability of HBSMCs, and the ability was enhanced by NAC treatment. These results demonstrate that CSE treatment induces cell death and reduces migration and contraction by increasing ROS generation in normal HBSMCs. These results suggest that CSE may induce airway change through cell death and reduction in migration and contraction of normal HBSMCs.

• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1837-1839
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• 2003

Recently deep interests have been paid on the effective generation of ozone, which has been widely used for water treatment, deoderization, color removal and chemical processing of exhausted smoke. The silent discharge reaction has been proposed as the most effective in the many ozone generation methods by electric discharge, because silent discharge excel others in the condition of high ozone generation yield and low power consumption. In this paper, ozone water generated system measure with silent discharge characteristics and pulsed power supply.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.629-634
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• 2016

In this study, we investigated the effect of factors that influence the measurement of smoke density using synthetic rubber flooring. The characteristics of rolling stock in an enclosed environment can cause enormous loss of life by smoke inhalation during fires inside passenger cars. The amount of smoke generation from interior materials for rolling stock is strictly restricted domestically and in other countries. Precise measurement of smoke density is therefore required to assess the fire performance of interior materials. Major factors that influence the measurement of smoke density include the uniformity of the specimen, the variations in conditions and instruments, and the operational and maintenance environment of the instruments. The contribution of factors was analyzed by estimating the uncertainty to investigate the contribution ratios of the major factors. The results show a contribution ratio of about 86% for the variation from the measurement of light transmission using a photomultiplier tube. Thus, this factor was the most representative for the measurement of smoke density. The contribution ratio of the other factors was low at about 11%, including irradiant flux conditions (${\pm}0.5 kW/m^2$) and the influence of the operational and maintenance environment of the instrument. These results were obtained using specimens with high uniformity.

• Tunnel and Underground Space
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• v.16 no.6 s.65
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• pp.526-535
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• 2006

An experimental study was carried out on a reduced scale tunnel model to grasp the behavioral feature of fire-induced smoke in the long tunnels. Based on Froude modeling, the 1/50 scaled tunnel model (20 m long) was constructed by acrylic tubes and paraffin gas was released inside the tunnel to simulate the 20 MW fire-induced smoke. me test results show, that after approximately 2 minutes of fire generation, was descended from the tunnel ceiling through the decrease of buoyancy, then it was symmetrically propagated about 90 meters for 4 minutes before jet fans were operated. The smoke was effectively controlled when the jet fans were operated and an air stream velocity was getting closed to reach a critical velocity (the minimum air velocity that requires to suppress the smoke spreading against the longitudinal ventilation flow during the tunnel fire situations). It was also found out that a range of smoke was spreaded about 3 meters from the origin of fire but the range was not propagated to the escape direction anymore. The early stage of the In operation, however, showed that the smoke was hardly controlled. It means that the operation of emergency ventilation system has many dangerous factors such as an intercepting breathing zone.

• Applied Chemistry for Engineering
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• v.18 no.5
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• pp.527-530
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• 2007

The binary liquid type fire retardant paint of polyurethane (alkyd resin) lacquer is developed to cover the defect of one liquid type white paint of chlorinated rubber used generally but which has weak surface and poor adhesive strength to the wood as well as generating much black smoke when it is firing. The properties of the composition of binary liquid type of white paint of polyurethane lacquer developed in this study for using to wood has shown that the better suppressed smoke generation and enhanced the adhesive strength to the wood than that of fire retardant white paint used.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2004.04a
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• pp.55-58
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• 2004

Phenolin resin, prepared form phenol and formaldehyde, is one of the oldest thermosetting resins available. Phenolic resins are cured via condensation polymerization with evolution of water, which in molding process is a big problem. The use of phenolic resins in glass fiber composites is growing, primarily due to their low flame spread, low smoke generation and low smoke toxicity properties. SMC of phenolics has been rearched since the 1986. The technology challenge was to match resin viscosity, handling and cure with those for the polyester SMC to avoid any special processing for fabricators and end users. Phenolic SMC was chosen because of the ease of molding to the required shape with light- weight, thin wall structure and with excellent fire protection.

• Journal of the Semiconductor & Display Technology
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• v.23 no.1
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• pp.110-116
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• 2024

Despite the continuous advancement of science and technology, fire accidents continue to occur without decreasing over time, so there is a constant need for a system that can accurately detect fires at an early stage. However, because most existing fire detection systems detect fire in the early stage of combustion when smoke is generated, rapid fire prevention actions may be delayed. Therefore we propose an early fire detection system that can perform early fire detection at a reasonable cost using LSTM, a deep learning model based on multi-gas sensors with high selectivity in the early stage of decomposition rather than the smoke generation stage. This system combines multiple gas sensors to achieve faster detection speeds than traditional sensors. In addition, through window sliding techniques and model light-weighting, the false alarm rate is low while maintaining the same high accuracy as existing deep learning. This shows that the proposed fire early detection system is a meaningful research in the disaster and engineering fields.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.44 no.2
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• pp.111-116
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• 2018

In cosmetics market, anti-pollution products recently come up with new solution for skin health. Environmental oxidation mechanisms are realized as bio-marker of atmospheric pollution upon skin by environmental pollutant such as ozone, UV rays, particulate matter (PM) as well as cigarette smoke. The exposure of cigarette smoke directly or indirectly causes the oxidation of the stratum corneum skin lipids, resulting in the conversion of squalene to squalene monohydroperoxide and/or generation of malondialdehyde (MDA) as a product of lipid peroxidation. The aim of this study is to see whether new cosmetics product containing red beet has anti-oxidation effect on skin exposed by cigarette smoke. So as to determine oxidative damage to human skin at biochemical level, each unit area of volar forearms was exposed to cigarette smoke through device (3.3 cm, diameter) for fifteen minutes, then measured MDA using standardized TBARS assay kit. Compared to negative control (untreated and unexposed area), the level of MDA was significantly increased at positive control (untreated and exposed area) more than 3.7 times, indicating the pollutant induced-oxidative damage on the skin barrier. Whereas, the pre-applied area with the cosmetics products containing red beet revealed a decrease of 25% compared with positive control. As reports, these data demonstrated that cigarette smoke induce peroxidation of stratum corneum skin lipids. Conclusively, we suggest that anti-pollution effect of the cosmetics product containing red beet is beneficial to prevent the oxidation of skin lipids by atmospheric pollution.