• Fire Science and Engineering
• /
• v.31 no.6
• /
• pp.107-111
• /
• 2017

The purpose of this study was to develop a Eco smoking booth that can effectively reduce hazardous pollutants generated during smoking and evaluate the efficiency and effectiveness of removing hazardous pollutants. The design and manufacture of an eco-friendly automatic smoking booth equipped with deodorizing facilities, such as inlet - HEPA filter - electrostatic precipitator (EP) - impregnated activated carbon - exhaust port, etc., and the efficiency of removing hazardous pollutants from inside and outside was measured and evaluated. The complex odor removal efficiency was 95.37% inside the smoking booth, and 97.38% at the exit of the preventive facility. The carbon monoxide removal efficiency was 94.25% in the inside and 98.32% in the outlet. In addition, the removal efficiency of particulate matter, (PM1, PM2.5, and PM10) inside the smoking booth was 98.59%, and 98.85% at the outlet. The total volatile organic compounds (TVOCs) decreased from $26,000{\mu}g/m^3$ to $5,203{\mu}g/m^3$ in the smoking booth, resulting in 79.99% removal efficiency. After the ventilator was operated, the measured effluent concentration was $5,019{\mu}g/m^3$, and the removal efficiency was 80.70%. Therefore, the smoking booth designed and manufactured through this study can be applied to the removal of harmful pollutants even in the small working environment in the future.

• The Korean Journal of Nuclear Medicine
• /
• v.32 no.1
• /
• pp.71-80
• /
• 1998

This study examines the levels of carbohydrate antigen 19-9(CA19-9) and cancer antigen 125(CA125) in serum and its related factors in healthy Korean population. Although CA19-9 and CA125 have been widely used tumor markers for gastroenteric cancers and ovarian cancer in Western countries, there are no information available on the serum levels of CA19-9 and CA125 in healthy population and the factors affecting the levels of these tumor markers in Korea. A cross-sectional study was performed to measure CA19-9 and CA125 among 76 healthy males and 95 healthy females in Korea. CA19-9 and CA125 were quantitated using solid-phase radioimmunoassay kits. Informations on the factors which might be related to the levels of these markers were collected by questionnaire(e.g., smoking, alcohol consumption, menstruation, oral pill use, breast-feeding history, etc.). There was no statistically significant difference in the mean of CA19-9 concentration between men(10.4 u/ml) and women(10.1 u/ml), whereas the mean of CA125 levels(11.2 u/ml) was higher in women than that(2.5 u/ml) in men. Although there was a statistically significant association between CA19-9 and average number of cigarette consumed per day(r=0.59, p=0.026) and total number of cigarettes consumed in women(r=0.74, p=0.003), the significance disappeared by multiple regression analysis after adjusting age and body mass index. Later age of menopause(p=0.035) and longer duration of breast-feeding(p=0.050) were significant predictors for CA125 levels in women by multiple regression analysis after adjusting age and body mass index. In conclusion, CA19-9 can be used as a stable tumor marker in clinical practices, however, menstruation and breast-feeding should be considered when CA125 is used in women.

• Journal of the Society of Disaster Information
• /
• v.11 no.1
• /
• pp.135-147
• /
• 2015

Recent underground common utility tunnels are underground facilities for jointly accommodating more than 2 kinds of air-conditioning and heating facilities, vacuum dust collector, information processing cables as well as electricity, telecommunications, waterworks, city gas, sewerage system required when citizens live their daily lives and facilities responsible for the central function of the country but it is difficult to cope with fire accidents quickly and hard to enter into common utility tunnels to extinguish a fire due to toxic gases and smoke generated when various cables are burnt. Thus, in the event of a fire, not only the nerve center of the country is paralyzed such as significant property damage and loss of communication etc. but citizen inconveniences are caused. Therefore, noticing that most fires break out by a short circuit due to electrical works and degradation contact due to combustible cables as the main causes of fires in domestic and foreign common utility tunnels fire cases that have occurred so far, the purpose of this paper is to scientifically analyze the behavior of a fire by producing the model of actual common utility tunnels and reproducing the fire. A fire experiment was conducted in a state that line type fixed temperature detector, fire door, connection deluge set and ventilation equipment are installed in underground common utility tunnels and transmission power distribution cables are coated with fire proof paints in a certain section and heating pipes are fire proof covered. As a result, in the case of Type II, the maximum temperature was measured as $932^{\circ}C$ and line type fixed temperature detector displayed the fire location exactly in the receiver at a constant temperature. And transmission power distribution cables painted with fire proof paints in a certain section, the case of Type III, were found not to be fire resistant and fire proof covered heating pipes to be fire resistant for about 30 minutes. Also, fire simulation was carried out by entering fire load during a real fire test and as a result, the maximum temperature is $943^{\circ}C$, almost identical with $932^{\circ}C$ during a real fire test. Therefore, it is considered that fire behaviour can be predicted by conducting fire simulation only with common utility tunnels fire load and result values of heat release rate, height of the smoke layer, concentration of O2, CO, CO2 etc. obtained by simulation are determined to be applied as the values during a real fire experiment. In the future, it is expected that more reliable information on domestic underground common utility tunnels fire accidents can be provided and it will contribute to construction and maintenance repair effectively and systematically by analyzing and accumulating experimental data on domestic underground common utility tunnels fire accidents built in this study and fire cases continuously every year and complementing laws and regulations and administration manuals etc.

• Journal of the Korean Institute of Gas
• /
• v.16 no.6
• /
• pp.107-114
• /
• 2012

Fire detection system is used for detection and alarm-generation of danger in case of fire. Most fire detection systems being used these days often malfunction from false positive and false negative errors. To improve detection reliability, an integrated fire detection algorithm using multi-senor information of heat, smoke and carbon monoxide detectors is suggested, then built and tested using the LabVIEW environment. Simulated using sensor measurement data offered by National Institute of Standards and Technology (NIST), possibility of reducing false positive and false negative errors is verified.

• Fire Science and Engineering
• /
• v.32 no.2
• /
• pp.1-6
• /
• 2018

The combustion characteristics of cypress wood coated with boric acid (BA) and ammonium pentaborate (APB) were examined using a cone calorimeter according to the ISO 5660-1 standard. As a result, the combined specimens of boric acid and ammonium pentaborate (BA/APB) led to an improved fire performance index due to their synergistic effect. In addition, the total heat release values of the specimen coated with the boron compounds were 6.1~14.1% lower than that of the base specimen. The total smoke release rate (TSR) of the specimens coated with the boron compound decreased throughout the combustion process, except for BA/APB. The maximum concentration of carbon monoxide was reduced by 15.8~25.5%. In general, wood treated with flame retardants has a lower fire hazard.

• The Korean Journal of Pesticide Science
• /
• v.12 no.3
• /
• pp.215-221
• /
• 2008

To assess the impact of molinate on freshwater aquatic organisms, acute and chronic toxicity studies for waterfleas were conducted. In acute toxicity studies for Daphnia magna, and Moina macrocopa, the 48-h $EC_{50}$ values were 11.4 and 8.3 mg/L respectively. And in reproduction toxicity studies for the same species, the NOEC's were 2.5 and 2.0 mg/L respectively. These results suggest that waterfleas have simillar sensitivity to molinate. On the other hand, the NOEC for 3-generation toxicity of moina macrocopa 0.16 mg/L, was much lower than those of acute values. This studies concludes that molinate has minimal risk to waterfleas in river.

• Journal of Korean Society for Atmospheric Environment
• /
• v.20 no.6
• /
• pp.715-727
• /
• 2004

This study was carried out to evaluate non-smoker's exposure levels to environmental tobacco smoke (ETS) in the air of offices in urban areas. A total of 65 offices were selected from two large cities, i.e. Daegu and Daejeon. The field sampling was conducted repeatedly in summer (1999) and winter (1999～2000). The measured ETS markers included respirable suspended particles (RSP as PM$_{40}$ ), vapor and particulate phase ETS markers, including nicotine, 3-ethnyl pyridine (3-EP), ultraviolet absorbing particulate matter (UVPM), fluorescing particulate matter (FPM), and solanseol in ETS particles (SolPM). RSP was measured gravimetrically by a microbalance. The particle samples were then used for the determination of particulate ETS markers by HPLC, while vapor phase markers determined by GC/NPD. The analytical methods were validated for repeatability, linearity, detection limits, and duplication precision. The concentrations of RSP and other ETS markers were significantly higher in smoking offices than non-smoking offices. Despite the similar smoking strength in each office for different seasons, the concentration levels of ETS components appeared to be higher in winter than summer. The contributions of ETS to RSP concentrations based on SolPM, FPM, and UVPM methods were estimated to be in the range of 15.2 ～ 25.3% in smoking offices, whereas 2.4 ～ 15.9% in non-smoking offices. The cooling and heating types did not affect significantly the concentrations of RSP and other ETS markers. Finally, further research issues were suggested to obtain more scientific information on the non-smoker's exposure to ETS with respect to the frame of risk assessment..

• Fire Science and Engineering
• /
• v.30 no.5
• /
• pp.100-107
• /
• 2016

Today, high-rise buildings expected to meet various needs and improve the quality of frequency of fire and the potential risks are increasing. In particular, the fire spread risk in the vertical direction is increasing. As a result there is a problem with delays in the evacuation time of occupants. To overcome this problem, there is a need to consider the structure of the building and develop a system for the early detection of fire by applying a fire alarm system according to the risk ranking. Therefore, this paper describes the vertical fire spread characteristics of a multistory double-skin and stairs structure with risk. The data were compared with that from the national and international fire alarms as well as with. smoke density, smoke detectors, visibility, and CO concentration using FDS. A fire alarm system for each structure is proposed.

• Fire Science and Engineering
• /
• v.34 no.4
• /
• pp.78-86
• /
• 2020

In this study, numerical simulations were performed on the air egress velocity of pressurization systems in an ancillary room when a fire occurred in an apartment house. The relationship between the air supply flow rate of a damper and air egress velocity at a fire door is predicted to be linear. Additionally, a minimum flow rate of the damper, which meets national fire safety standards for air egress velocity, i.e., 0.7 m/s can be estimated. Air egress velocity at the fire door is analyzed according to the supply air direction and installation height of the damper. When the damper has an upward supply air direction and is installed at a high level, the egress velocity at the top section of the fire door is larger, whereas the soot concentration at the ancillary room is lower than when the supply direction of the damper is downward. Therefore, it is found that increasing the air egress velocity at the top section of the fire door helps to efficiently prevent the inflow of smoke.

• Fire Science and Engineering
• /
• v.20 no.4 s.64
• /
• pp.72-76
• /
• 2006

Polymer/clay nanocomposites have generated considerable interests in the past decade because adding just tiny amount of clay to the polymer matrix could produce a dramatic enhancement in physical, thermal and mechanical properties. Smectite clays, such as montmorillonite (MMT), are of great industrial value because of their high aspect ratio, plate morphology, intercalative capacity, natural abundance and low cost. In this study, PE/MMT nanocomposites were directly prepared by melt intercalating PE and the modified clay. The nanostructure was verified by X-ray diffraction (XRD) and transmission electron microscopy (TEM), and their flame retardant properties were measured and discussed by limiting oxygen index (LOI), char yield and smoke mass concentration. And their thermal stabilities were measured by differential thermogravimetric (DTG) and thermogravimetric analysis (TGA). The PE/MMT nanocomposites proved more effective the conventional composites in reinforcement. Two functions in the thermal stability of the PE/MMT nanocomposite, one is the barrier effect to improve the thermal stability, and another is catalysis, leading to a decrease of the thermal stability. The flammability was greatly decreased due to the formation of the clay-enriched protective char during the combustion.