• 한국가스학회지
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• 제11권2호통권35호
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• pp.65-70
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• 2007

LP 가스의 폭발현상 및 위험성을 평가하기 위하여, 산소농도변화와 LP 가스의 농도에 따른 혼합가스 조성을 변화시켜 실험을 행하였다. 산소농도 21%에서 LP 가스의 농도가 증가할수록 폭발하한계는 낮아졌으며, 최소산소농도(MOC, Minimum Oxygen Concentration)는 1.0 bar, 1.5 bar, 2.0 bar에서 각각 14.5%, 12.0%, 11.5%로 낮아졌다. 최대폭발압력은 압력이 증가할 경우 $6.46kg/cm^2,\;9.41kg/cm^2,\;13.49kg/cm^2$로 증가하였으며, LP 가스의 초기압력이 클수록 화염의 전파속도가 증가하였다.

• 한국가스학회지
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• 제9권3호
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• pp.9-14
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• 2005

변성가스의 폭발특성을 평가하기 위하여, 산소농도 변화와 수소의 첨가에 따른 변성가스 조성을 변화시켜 폭발거동에 대한 실험을 행하였다. 이러한 실험을 행한 결과 산소농도 $21\%$에서 변성가스와 수소의 농도가 증가할수록 폭발하한계는 낮아졌으며, 산소농도 $6\%$에서 폭발한계산소농도를 구하였다. 변성가스의 최대폭발압력은 $4.61 kg_f/cm^2$의 최적값을 얻었고, 이때 최대폭발압력상승속도는 변성가스 농도 $40\%$에서 $130.75 kg_f/cm^2/s$를 구하였다. 또한 폭발에 필요한 최소점화에너지는 변성가스 농도 $50\%$에서 0.13 mJ를 구하였다.

• 한국태양에너지학회 논문집
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• 제26권1호
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• pp.65-71
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• 2006

This study describes to analyze variation of carbon dioxide gas concentration by experimental and theoretical method according to the using patterns of ventilation system in a model classroom. Concentration of $CO_2$ gas varied by the occupancy and the ventilation systems are operating or not. More than 850 CMH ventilation system can maintain $CO_2$ gas concentration lower than 1,000 ppm along the class time and can be adopted the government guideline. Theoretical modeling of the concentration was performed at well-mixed ideal condition. Delays of concentration decay were shown at each case compared to actual.

• 약학회지
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• 제37권5호
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• pp.458-462
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• 1993

Blood toluene concentrations of thirty nine Korean toluene-exposed workers in shoes making factory were checked by headspace-gas chromatographic analysis. Air toluene concentrations in each worker's working region also checked by personal sampler during workshift and analyzed by gas chromatography. The range of blood toluene concentration was 0.15-0.84mg/L. The range of toluene concentration of each worker's working area was 8.46-189.9ppm. The correlation between blood and air concentration of toluene was 0.824.

• 전기학회논문지P
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• 제51권3호
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• pp.132-136
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• 2002

In this study, we analyzed the luminous efficiencies of Ne-Xe-Ar and He-Ne-Xe-Ar mixing gas in compared with those of Ne-Xe and He-Ne-Xe mixing gas to improve luminous efficiency by adding a small amount of Ar gas. At the Xe 4%, the brightness of Ne-Xe and He-Ne-Xe mixing gas is higher than others. As the Xe % increases, power consumption decreases. Thus, in the Ne-Xe and He-Ne-Xe mixing gas of Xe 4%, we obtained maxium luminous efficiency. The Ar concentration is varied from 0.1% to 0.7% in this study. The luminous efficiency of the Ne-Xe(4%) mixing gas is improved to 1.16 and 1.13 lm/W by adding an Ar concentration of 0.4% and 0.5%, respectively. The luminous efficiency of the He-Ne-Xe(4%) (He : Ne = 7 : 3) mixing gas is considerably improved by adding an Ar concentration of above 0.3%. The maximum luminous efficiency of this mixing gas is 1.38 lm/W at the condition of adding an Ar concentration of 0.5%.

• 한국멀티미디어학회논문지
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• 제25권2호
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• pp.189-196
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• 2022

We have developed an embedded based environment sensing module with high-resolution temperature, humidity and gas sensors to detect gas leakage under the condition of LNG injection. The developed sensing module have linearity with gas concentration. We have confirmed the developed sensing module could detect LNG gas concentration of 5 cmol/mol and 15 cmol/mol, which are gas concentration at risk of explosion. The response time of the developed module was fast within 8 seconds. Therefore it can be used to detect LNG gas leakage.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 춘계학술대회 논문집
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• pp.194-197
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• 2008

We measured the efficiency and flue gas concentration of a 90kW woodchip boiler which is for heating water of lodging. At nominal operating condition, the fuel, woodchip is fed into the boiler at a rate of 22.6 kg/h. In order to determine the efficiency of the boiler, we measured the water flow rate, woodchip flow rate, heating value and water content of woodchip, temperature of inlet and outlet of heating water. The results of test show that the power output of the woodchip boiler is 90.0 kW(77,400 kcal/h) and the thermal efficiency of the boiler is 88.5%. By using a gas analyser, flue gas concentrations are measured. The results show that O2 in the flue gas is 10.2%, CO concentration is 393 ppm and NOx concentration is 74 ppm.

• Safety and Health at Work
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• 제1권1호
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• pp.98-101
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• 2010

This study explored the health hazard of those exposed to methylene chloride by assessing its atmospheric concentration when a tear gas mixture was aerially dispersed. The concentration of methylene chloride ranged from 311.1-980.3 ppm (geometric mean, 555.8 ppm), 30 seconds after the dispersion started. However, the concentration fell rapidly to below 10 ppm after dispersion was completed. The concentration during the dispersion did not surpass the National Institute for Occupational Safety and Health 'immediately dangerous to life or health' value of 2,300 ppm, but did exceed the American Conference of Governmental Industrial Hygienists excursion limit of 250 ppm. Since methylene chloride is highly volatile (vapor pressure, 349 mmHg at $20^{\circ}C$), the post-dispersion atmospheric concentration can rise instantaneously. Moreover, the o-chlorobenzylidenemalononitrile formulation of tear gas (CS gas) is an acute upper respiratory tract irritant. Therefore, tear gas mixtures should be handled with delicate care.

• 한국가스학회지
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• 제15권3호
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• pp.26-30
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• 2011

개방형 순간 가스온수기는 설치와 관리가 적절히 되지 않아 일산화탄소 중독과 질식과 같은 인명사고를 발생시킬 수 있다. 연소기에 공기가 충분히 공급되지 않거나 배기구가 막히면 배기가스 중의 일산화탄소(CO)의 농도가 증가하는 특성을 보인다. 본 연구는 가정집에서 사용 중인 개방형 가스온수기를 회수하여 연소기 주변 공기 중산소농도 및 배기가스 중 CO농도의 변화를 확인하였다. 환기구 면적에 따른 산소농도 측정 실험에서 환기구의 면적이 바닥면적의 3.5%에서 산소농도가 약 17.7%로 나타났고, 배기구를 폐쇄한 상태에서 CO농도를 측정한 결과 4,000ppm이상이 측정되었다. 따라서 정기적으로 배기구를 점검하는 것이 환기구 크기보다 일산화탄소 중독사고를 예방하기 위하여 중요하다.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.172-175
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• 2008

In the last five years, 45 people died and 104 were wounded because of carbon monoxide poisoning accident. CO poisoning accident is higher than any other gas accident in the rate of deaths/incidents. 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 CO gas 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 CO alarm was made certain and suggested.