• Title/Summary/Keyword: carbon monoxide

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CFD-based simulation of fire-induced smoke and carbon monoxide transportation in the single compartment (CFD를 이용한 단일 구획 공간에서의 연기와 CO 확산 시뮬레이션)

  • Son, Yoon-Suk;Kim, Hyeong-Gweon;Oh, Hyung-Sik;Kim, Tae-Ok;Shin, Dong-Il
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 2008.04a
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    • pp.290-293
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    • 2008
  • In this study, the Computational Fluid Dynamics (CFD) has been used to analyze the smoke movement and the carbon monoxide concentration distribution, both vertically and longitudinally, in a compartment, based on conservation laws. The Fire Dynamics Simulator (FDS) developed by National Institute of Standards and Technology (NIST) was used for numerical simulations using Reynolds averaged Navier-Stokes equations (RANS) model to solve for time-averaged properties. Results show, as a function of time, a detailed distribution of temperature and carbon monoxide concentration changing against the height above the floor and those changes alongside the distance away from the fire source. Fire-induced smoke and toxic gases like CO are more dangerous in a confined space. The result of study may contribute in designing the smoke evacuation system based on the precise tenable condition.

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Analysis of Mechanism for Diffusion of Incomplete Combustion Gas Released from Domestic Gas Boiler (가정용 보일러의 불완전연소가스 누출확산 메커니즘 해석)

  • Kang, Seung-Kyu;Choi, Kyung-Suhk;Yoon, Joon-Yong
    • Proceedings of the KSME Conference
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    • 2008.11b
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    • pp.2868-2873
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    • 2008
  • Carbon Monoxide(CO) poisoning accident is higher than any other gas accident in the rate of deaths/incidents. In the last five years, 36 people died and 104 were wounded because of carbon monoxide poisoning accident. Most of these CO poisoning accidents were caused by defective exhaust tube in the old gas boiler and multi-use facility. In this study, the spread of incomplete combustion gas(CO) released from leakage hole of exhaust tube was analyzed by computational flow modeling and concentration measuring test. CO gas leaked form exhaust tube in a building was highest concentrated near the ceiling and formed the circular currents along the walls. Through these experiments and simulation, the reasonable installation location of carbon monoxide alarm was made certain and suggested.

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Catalytic Activity of $Nd_{1-x}Sr_xCoO_{3-y}$ on the Oxidation of Carbon Monoxide

  • Kim, Keu-Hong;Kim, Seong-Han;Lee, Dong-Hoon;Kim, Yoo-Young;Choi, Jae-Shi
    • Bulletin of the Korean Chemical Society
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    • v.12 no.1
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    • pp.35-39
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    • 1991
  • The catalytic activity of $Nd_{1-x}Sr_xCoO_{3-y}$, $0{\leq}x{\leq}0.75$ and $0.001{\leq}y{\leq}0.103$, on the oxidation of carbon monoxide has been investigated from the structure analyses of the catalysts by X-ray diffraction and infrared spectroscopy and the measurements of the oxidation and adsorption rates of carbon monoxide. The catalytic activity is found to be correlated with Sr substitution (x) and nonstoichiometry (y). The oxidation power of carbon monoxide increases continuously with increasing Sr substitution without oxygen, but increases with Sr substitution up to x = 0.25 and then is almost constant at larger x values up to x = 0.75 with oxygen. This change of catalytic activity is explained by the oxidation-reduction properties of the catalyst due to the variation of nonstoichiometry.

Barrier Height from Ⅴ-Ⅰ Characteristics of Semiconductor Contact: Reaction of Absorbed Oxygen with Carbon Monoxide on ZnO (1010)

  • 김혜정;한종수
    • Bulletin of the Korean Chemical Society
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    • v.18 no.2
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    • pp.149-151
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    • 1997
  • Barrier height on the surface was monitored at 77 K by observing the inflection of V-I characteristics of ZnO(1010)-ZnO(1010) contact in the surface reaction of oxygen species with carbon monoxide. The contact showed inflections at 10-20 mV and 10-50 mV for the sample adsorbed oxygen at 298 K and 573 K, respectively. When the sample adsorbed oxygen at 573 K was exposed to carbon monoxide at 298 K and 573 K, inflections were observed at 10-40 mV and 10-30 mV, respectively. The results indicated that the adsorption of oxygen on ZnO increased the surface barrier height, and the reaction of carbon monoxide with the oxygen-preadsorbed (at 573 K) ZnO decreased the surface barrier height.

Trend Analysis of Wildland Fires and Their Impacts on Atmospheric Environment over East Asia

  • Shin, Sung-Kyun;Lee, Kwon-Ho
    • Asian Journal of Atmospheric Environment
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    • v.10 no.1
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    • pp.22-31
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    • 2016
  • Active fire products from Moderate Resolution Imaging Spectroradiometer (MODIS) satellite observation during the 16 years from 2000-2015 were analyzed to estimate spatial and temporal variations of wildland fires over East Asia (region of interest: $20^{\circ}N-55^{\circ}N$, $100^{\circ}E-150^{\circ}E$). GLOBCOVER 2009 land cover data were also used to investigate the trend in wildfire occurrence with respect to each land cover type. Statistical analysis showed that the highest number of wildland fires occurred in the evergreen and vegetation covered areas, and strong seasonal variations were found in these areas. Total numbers of fires were 283,683 and 202,543, respectively. In particular, the wildland fires in croplands occurred mainly during summer season and distinguishable increasing trends were found. The correlations between number of wildland fires and air pollutants, such as black carbon, organic matter, and carbon monoxide, were also calculated in order to investigate the intensity of the air pollution caused by the wildland fires. Positive correlation between total column carbon monoxide contents and the occurrence of wildland fire was found. In addition, this correlation was higher than the correlation between fire occurrence and black carbon or organic matter. These results indicate that a significant amount of carbon monoxide originated from the wildland fires and influenced the regional atmospheric environment in East Asia.

A Method to Prevent CO Poisoning from Instantaneous Water Heaters (순간 가스온수기의 CO 중독사고 예방에 관한 연구)

  • Ahan, Jeong-Jin;Yeo, Chang-Hoon;Jo, Young-Do
    • Journal of the Korean Institute of Gas
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    • v.15 no.3
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    • pp.26-30
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    • 2011
  • Instantaneous water heater being not properly installed and not adequately maintained may produce fatal accidents due to carbon monoxide poisoning and suffocation. Insufficient supply of air into the gas appliance for complete burning of the fuel or blocking the outlet of the combustion gas could be a cause to increase carbon monoxide concentration in the exhaust gas of the gas appliance. In this work, the experiments are done with a collected instantaneous water heater using in domestic and the concentration of oxygen near the gas appliance and carbon monoxide in exhaust gas are observed to investigate the risk of instantaneous water heater. The concentration of oxygen near the gas appliance is reduced until 17.7% for the ratio of the ventilation area and floor area being 3.5%. If the outlet of combustion gas is blocked, the carbon monoxide concentration is steeply increasing more than 4,000ppm. Therefore, periodic checking the outlet of combustion gas is more important than vent area to reduce the risk of carbon monoxide poisoning.

Analysis of Patients with Acute Carbon Monoxide Poisoning in one Hospital (일개 병원에서의 일산화탄소 중독증으로 내원한 환자에 대한 분석)

  • Kim Kyung Hwan;Kim Ah Jin;Shin Dong Wun;Rho Jun Young
    • Journal of The Korean Society of Clinical Toxicology
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    • v.3 no.1
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    • pp.27-32
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    • 2005
  • Purpose: The frequency of carbon monoxide poisoning has been decreased in the interior of the Korea. But occasionally it is occurred and the risk of exposure is high in working place so far. Because of the characteristics of gas, the detection of exposure and poisoning could be delayed and fatality is high. We should apprehend of carbon monoxide poisoning. So we would report analysis of patients with carbon monoxide poisoning. Methods: A retrospective review of CO poisoned patients visited emergency department from January 2000 to December 2004 was conducted. Results: 24 patients were enrolled. Their average of age was $37.6\pm20.9$ years old and COHb was $19.4\pm13.32\%$. The blood level of initial COHb and mental status on arrival were not correlated each other. The blood level of initial COHb and loss of consciousness were not correlated, too. Initial electrocardiography (EKG) was not correlated with cardiac enzymes such as CK-MB and troponin I. But base excess was correlated with mental status on arrival and complication such as rhabdomyolysis. Hyperbaric oxygen therapy was correlated with base excess and mental status on arrival. Conclusion: The clinical features of carbon monoxide poisoning are nonspecific. For proper diagnosis, it is important that we should consider patient's environment and take patient's history carefully. The blood level of initial COHb does not reflect severity of poisoning accurately. So We should determine the treatment of choice depending on patient's status.

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Effect of Auricular Acupressure Therapy on Decreasing Smoking rates, Desire for Smoking, and Exhaled Carbon Monoxide in Male College Students (이압요법이 흡연 남자대학생의 흡연량, 흡연욕구, 호기 일산화탄소에 미치는 효과)

  • Kwon, Oh Yun;Song, Jung Hee;Park, Kyung Sook
    • The Korean Journal of Rehabilitation Nursing
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    • v.18 no.2
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    • pp.88-97
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    • 2015
  • Purpose: This study was conducted to investigate the effect of auricular acupressure therapy on decreasing smoking rates, desire for smoking, and exhaled carbon monoxide in male college students. Methods: The quasi-experimental, nonequivalent control group pretest-posttest design was used in this study. The participants (n=56) were assigned to the experimental group (n=29) that received auricular acupressure therapy or the control group (n=27) that received placebo therapy. The therapy was applied for 5 days followed by 1 or 2 days of rest. The therapy was repeated 2 times. To identify the effect of the experimental treatments, assessments of smoking rates, desire for smoking and exhaled carbon monoxide were measured. Data were analyzed using $x^2$ test, Fisher's exact test, t-test and Repeated measure ANOVA with the SPSS version 21.0 program. Results: The experimental group showed significantly lower smoking rates (t=6.60, p<.001), desire for smoking (t=3.37, p=.002) and exhaled carbon monoxide levels (t=6.22, p<.001) after application of the therapy. Significant group${\times}$time interaction effect was found in exhaled carbon monoxide levels between the experimental group and the control group (F=8.73, p=.001). Conclusion: Auricular acupressure therapy was considered to likely be useful as a therapeutic intervention for smoking cessation in male young adults.

Removal of Carbon Monoxide from Anthracite Flue Gas by Catalytic Oxidation (I) (촉매반응에 의한 연탄 연소가스로부터 일산화탄소의 제거 (제1보))

  • Chung Ki Ho;Lee, Won Kook
    • Journal of the Korean Chemical Society
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    • v.20 no.5
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    • pp.431-437
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    • 1976
  • On the condition of adequate air supply, complete removal of carbon monoxide,occurred above $650^{\circ}C$. Using catalysts, the oxidation of carbon monoxide occurred at lower temperatures; on both $MnO_2 \;and\;30%\;MnO_2-70%\;CuO\;at\;250{\circ}C,\;on\;CuO\;at\;450{\circ}C,\;on\;50%\;MnO_2-50%\;CuO\;at\;200{\circ}C,\;and\;on\;70%\;MnO_2-30%\;CuO\;at\;180{\circ}C$. Manganese dioxide (p-type) showed higher activity than cupric oxide (n-type) and a catalyst consisting of 60% $MnO_2-40%$ CuO had the highest activity of all the $MnO_2$-CuO mixture. Over the range of transitional temperature, carbon monoxide removal efficiency decreased linearly with increasing inlet carbon monoxide concentration while temperature was fixed. Residence time of gases in the catalytic reactor, in the range of 0.9 to 1.8 seconds, gave no effect on carbon monoxide conversion.

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