• Title, Summary, Keyword: 일산화탄소

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Study on the Fire Risk Prediction Assessment due to Deterioration contact of combustible cables in Underground Common Utility Tunnels (지하공동구내 가연성케이블의 열화접촉으로 인한 화재위험성 예측평가)

  • Ko, Jaesun
    • Journal of the Society of Disaster Information
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    • v.11 no.1
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    • pp.135-147
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    • 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.

A Comparison of Gases and Heavy Metals in Blood between Urban and Rural Teenager (도시(都市)와 농촌(農村) 약년자(若年者)의 혈액(血液)가스 및 중금속(重金屬) 함량(含量) 비교(比較))

  • Lee, Sang-Sook;Kim, Doo-Hie
    • Journal of Preventive Medicine and Public Health
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    • v.18 no.1
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    • pp.129-136
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    • 1985
  • This paper is carried out to determine the venous blood gas components and heavy metals, such as lead, cadmium and copper, in blood between urban and rural teenager. The subjects were 34 in urban, Taegu city and 37 in rural, Euisung-Gun. But smokers were excluded. The specimens were sampled in May, 1985. The heavy metals were analyzed by atomic absorption spectrophotometry (IL. 551) and carboxy-Hb, Met-Hb, Hb, $O_2\;and\;CO_2$, blood gas analyzer (IL. 1301) and CO-oximeter (IL. 282). In urban group, $PO_2\;and\;O_2-Hb$ were significantly lower than in rural (p<0.01, p<0.03, respectively), and ${HCO_3}^{-}\;and\;TCO_2$ were significantly higher than in rural (p<0.01, p<0.01, respectively). CO-Hb concentration was rather higher in the rural group than the urban (p<0.03), other Met-Hb was higher in urban group than in the rural (p<0.01). Lead and cadmium were also significantly higher in the urban group (p<0.03, p<0.02, respectively).

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A Studs on Farmers Syndrome and Its Risk Factors of Vinylhouse Workers and Evaluation of Risk Factors of Vinylhouse Works (일부 농촌지역 비닐하우스 농사자들의 작업환경 및 농부증 실태와 관련요인평가)

  • Lee, Jung-Jeung
    • Journal of agricultural medicine and community health
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    • v.29 no.1
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    • pp.101-119
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    • 2004
  • Objectives: In order to estimate risk factors affecting the health of vinylhouse workers and harmful environments in vinylhouse working. Methods: The investigator performed questionnaires and laboratory examinations on 102 vinylhouse workers and 69 farmers in 7 myoens (Korean subcounties). one eup (a Korean town), Goryeong-gun, Gyeongsangbuk-do between April 8 and 18, 2004 (for 11 days), and measured the heavy metal in the air and the soil, temperature, humidity, air current, harmful gases in vinylhouses. Results: Even in cloudy days, the temperature in vinylhouses in daylight was $33.4^{\circ}$ and the temperature difference between inside and outside vinylhouses was around $16^{\circ}$. Oxygen concentration was similar inside and outside vinylhouses, while carbon dioxide concentration was lower inside than outside vinylhouses. Carbon monoxide was not detected. In the air inside vinylhouses, cadmium was not detected. Lean concentration in the soil was lower inside vinylhouses than outside vinylhouses at surface, while cadmium concentration was similar inside and outside vinylhouses in the soil except some areas. Out of male vinylhouse workers. 16.4---- were positive farmer's syndrome and 49.2---- were suspicious, while out of females, 41.5---- were positive and 46.3---- were suspicious. Out of male farmers, 30.4---- were positive farmer's syndrome, while out of female farmers, 60.0---- were positive and 28.3---- were suspicious. There was no difference between vinylhouse workers and farmers in the distribution of hypertension and abnormal liver function, while diabetes mellitus was more common in farmers than in vinylhouse workers. Vinylhouse working, sex, and hours of farming per day were selected as significant variables affecting farmer's syndrome in this study, and the rate of positive farmer's syndrome was rather lower in vinylhouse workers than in farmers. Females were higher than males in the rate, and those who farmed at least 10 hours per day were higher in the rate than those who farmed less than 10 hours per day. Out of the vinylhouse workers, no differences were found between the distribution of farmer's syndrome and farming-related variables such as the total period of farming, the size of farm land, the mean farming hours per day, the number of family members who farm together, the frequency of scattering agricultural chemicals. In addition, there were no differences between the distribution and the wearing masks and protectors and personal sanitation among those who scattered agricultural chemicals by themselves. There were no differences found in blood lean concentration, urinary cadmium concentration, serum cholinesterase, and hemoglobin according to the distribution of farmer's syndrome. In the vinylhouse workers, females were higher than males in the rate of farmer's syndrome, and those who farmed at least 10 hours per day were higher in the rate than those who farmed less than 10 hours per day. Meanwhile, the rate was lower in those who slept at least 8 hours a day than in those who slept less than 8 hours. Conclusions: In conclusion, the physical environments inside vinylhouses were harmful, but no significant difference was found in harmfulness of the chemical environments. The chronic diseases such as farmer's syndrome. hypertension, diabetes, and dyshepatia were not common in the vinylhouse workers than in the farmers. Meanwhile, farmer's syndrome was more common in the vinylhouse workers who worked longer and slept less.

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A Stochastic Study for the Emergency Treatment of Carbon Monoxide Poisoning in Korea (일산화탄소중독(一酸化炭素中毒)의 진료대책(診療對策) 수립(樹立)을 위한 추계학적(推計學的) 연구(硏究))

  • Kim, Yong-Ik;Yun, Dork-Ro;Shin, Young-Soo
    • Journal of Preventive Medicine and Public Health
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    • v.16 no.1
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    • pp.135-152
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    • 1983
  • Emergency medical service is an important part of the health care delivery system, and the optimal allocation of resources and their efficient utilization are essentially demanded. Since these conditions are the prerequisite to prompt treatment which, in turn, will be crucial for life saving and in reducing the undesirable sequelae of the event. This study, taking the hyperbaric chamber for carbon monoxide poisoning as an example, is to develop a stochastic approach for solving the problems of optimal allocation of such emergency medical facility in Korea. The hyperbaric chamber, in Korea, is used almost exclusively for the treatment of acute carbon monoxide poisoning, most of which occur at home, since the coal briquette is used as domestic fuel by 69.6 per cent of the Korean population. The annual incidence rate of the comatous and fatal carbon monoxide poisoning is estimated at 45.5 per 10,000 of coal briquette-using population. It offers a serious public health problem and occupies a large portion of the emergency outpatients, especially in the winter season. The requirement of hyperbaric chambers can be calculated by setting the level of the annual queueing rate, which is here defined as the proportion of the annual number of the queued patients among the annual number of the total patients. The rate is determined by the size of the coal briquette-using population which generate a certain number of carbon monoxide poisoning patients in terms of the annual incidence rate, and the number of hyperbaric chambers per hospital to which the patients are sent, assuming that there is no referral of the patients among hospitals. The queueing occurs due to the conflicting events of the 'arrival' of the patients and the 'service' of the hyperbaric chambers. Here, we can assume that the length of the service time of hyperbaric chambers is fixed at sixty minutes, and the service discipline is based on 'first come, first served'. The arrival pattern of the carbon monoxide poisoning is relatively unique, because it usually occurs while the people are in bed. Diurnal variation of the carbon monoxide poisoning can hardly be formulated mathematically, so empirical cumulative distribution of the probability of the hourly arrival of the patients was used for Monte Carlo simulation to calculate the probability of queueing by the number of the patients per day, for the cases of one, two or three hyperbaric chambers assumed to be available per hospital. Incidence of the carbon monoxide poisoning also has strong seasonal variation, because of the four distinctive seasons in Korea. So the number of the patients per day could not be assumed to be distributed according to the Poisson distribution. Testing the fitness of various distributions of rare event, it turned out to be that the daily distribution of the carbon monoxide poisoning fits well to the Polya-Eggenberger distribution. With this model, we could forecast the number of the poisonings per day by the size of the coal-briquette using population. By combining the probability of queueing by the number of patients per day, and the probability of the number of patients per day in a year, we can estimate the number of the queued patients and the number of the patients in a year by the number of hyperbaric chamber per hospital and by the size of coal briquette-using population. Setting 5 per cent as the annual queueing rate, the required number of hyperbaric chambers was calculated for each province and for the whole country, in the cases of 25, 50, 75 and 100 per cent of the treatment rate which stand for the rate of the patients treated by hyperbaric chamber among the patients who are to be treated. Findings of the study were as follows. 1. Probability of the number of patients per day follows Polya-Eggenberger distribution. $$P(X=\gamma)=\frac{\Pi\limits_{k=1}^\gamma[m+(K-1)\times10.86]}{\gamma!}\times11.86^{-{(\frac{m}{10.86}+\gamma)}}$$ when$${\gamma}=1,2,...,n$$$$P(X=0)=11.86^{-(m/10.86)}$$ when $${\gamma}=0$$ Hourly arrival pattern of the patients turned out to be bimodal, the large peak was observed in $7 : 00{\sim}8 : 00$ a.m., and the small peak in $11 : 00{\sim}12 : 00$ p.m. 2. In the cases of only one or two hyperbaric chambers installed per hospital, the annual queueing rate will be at the level of more than 5 per cent. Only in case of three chambers, however, the rate will reach 5 per cent when the average number of the patients per day is 0.481. 3. According to the results above, a hospital equipped with three hyperbaric chambers will be able to serve 166,485, 83,242, 55,495 and 41,620 of population, when the treatmet rate are 25, 50, 75 and 100 per cent. 4. The required number of hyperbaric chambers are estimated at 483, 963, 1,441 and 1,923 when the treatment rate are taken as 25, 50, 75 and 100 per cent. Therefore, the shortage are respectively turned out to be 312, 791. 1,270 and 1,752. The author believes that the methodology developed in this study will also be applicable to the problems of resource allocation for the other kinds of the emergency medical facilities.

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Importance of Carbon Monoxide Transfer Coefficient (KCO) Interpretation in Patients with Airflow Limitation (기류제한 환자의 일산화탄소확산능 해석에서 폐용적 보정의 의의)

  • Seo, Yong Woo;Choi, Won-Il;Lee, Jeong Eun;Park, Hun Pyo;Ko, Sung Min;Won, Kyoung Sook;Keum, Dong Yoon;Lee, Mi-Young;Jeon, Young June
    • Tuberculosis and Respiratory Diseases
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    • v.59 no.4
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    • pp.374-379
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    • 2005
  • Background : The single-breath carbon monoxide diffusion capacity (DLCO) and the per unit alveolar volume (KCO; $D_LCO/VA$) gave discordant values when there was an abnormal alveolar volume (VA). However, the clinical significance of the discordant values in patients with airflow limitation has not been examined. This study investigated the $D_LCO$ and KCO changes after improving the airflow limitation. Methods : The baseline $D_LCO$ and KCO with lung volume were measured in patients with an airflow obstruction. The effective alveolar volume was measured using the single-breath $CH_4$ dilution method. The patients divided into two groups according to the baseline values: (1) increased KCO in comparison with the $D_LCO$ (high discordance) (2) decreased or not increased KCO in comparison with the $D_LCO$ (low discordance). The diffusion capacity and lung volume were measured after treatment. Results : There was no significant difference in the baseline lung volumes including the $FEV_1$ and FVC between the two groups. The $FEV_1$ and FVC were significantly increased in the high discordance group compared with the low discordance group after treating the airflow limitation. The $D_LCO$ and alveolar volume were significant higher in the high discordance group compared with the low discordance group while the TLC was not. Conclusion : The discordance between the $D_LCO$ and KCO could be translated into an airflow reversibility in patients with an airflow limitation.