• Title/Summary/Keyword: Smoke

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Scientific Evidences of Thirdhand Smoke (3차 간접흡연의 과학적 증거의 고찰)

  • Lee, Ki-Young
    • Journal of Environmental Health Sciences
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    • v.36 no.2
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    • pp.77-81
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    • 2010
  • Tobacco smoking and secondhand smoke exposure are linked to a number of adverse health outcomes. There is a new concept of thirdhand smoke that is residual tobacco smoke contamination remained after the cigarette is extinguished. This paper reviews published studies examining the residual tobacco smoke. Tobacco smoke can be attached to various surfaces and reemitted to air for long period of time. The dynamic process can allow thirdhand smoke exposure to tobacco smoke without direct exposure to secondhand smoke. One critical evidence of the thirdhand smoke exposure was significantly high urinary cotinine level of infant who did not have direct secondhand smoke exposure. Potential exposure to new and more potent chemicals generated from chemical reactions between residual tobacco smoke and ambient air pollutants can get more attention. Considering toxicity and exposure route, children are uniquely susceptible to thirdhand smoke exposure. The review provides strong background information for thirdhand smoke but warrant more researches on this issue.

A Study on Certification Requirements and Means of Compliance about In-Flight Smoke (비행 중인 항공기에 발생할 수 있는 연기에 대한 인증기준 및 적합성 입증방법)

  • Jeong, Bonggu;Jin, Yongkwon;Kim, Yougwang;Park, Guenyoung
    • Journal of Aerospace System Engineering
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    • v.1 no.4
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    • pp.7-12
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    • 2007
  • From the beginning of aviation history, in-flight smoke/fire events have been a serious issue. As aircraft are getting larger and are becoming more auto-piloted and aircraft systems are getting more complex, it is an increasing risk of in-flight smoke/fire accidents accompanied with fire events. Therefore, we review the statistics of fire/smoke accidents in order to enhance an understanding for risk of in-flight smoke events, and present the certification requirements for smoke per KAS Part 25. In addition, we provide acceptable methods of complying with related requirements, such as smoke detection test, smoke penetration test and smoke evacuation test.

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EFFECT OF CIGARETTE PAPER ON CIGARETTEAPPEARANCE BURN RATE AND SIDESTREAM SMOKE

  • Jr Vladimir Hampl
    • Proceedings of the Korean Society of Tobacco Science Conference
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    • 2000.05a
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    • pp.12-21
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    • 2000
  • The smoke from a burning cigarette is classified as mainstream, which is the smoke inhaled by the smoker during a puff, and sidestream, which is defined by ISO 10185 as all smoke which leaves a cigarette during the smoking process other than from the butt end. Most of the sidestream smoke is generated during static burn, that is, in between puffs. The amount of sidestream smoke generated by a cigarette depends on the cigarette construction, tobacco blend, and properties of the cigarette paper, The main paper properties affecting sidestream smoke generation are: porosity, basis weight, type and amount of filler, type and amount of burn additive.Sidestream smoke is composed of a visible phase (small liquid droplets) and an invisible phase (gaseous molecules). This paper focuses on the visible portion of the sidestream smoke. Optical methods, which are based on the relationship between light scattering and density of the rising plume of smoke, have been used successfully by the industry. However, the present trend is to use gravimetric methods where the particulate matter is captured on a Cambridge(R) filter pad and weighed. The gaseous portion of the sidestream smoke, which does not contribute to the visible sidestream smoke, passes through the Cambridge filter pad.Sidestream smoke reduction is achieved by modifying certain mass transport processes occurring in a smoldering cigarette. There are four main pathways for reducing sidestream smoke: A) less tobacco burned, B) slower rate of tobacco combustion, C) more efficient trapping of smoke by the cigarette paper, and D) more complete combustion of tobacco. This paper discusses how the physical properties of paper and cigarette construction affect sidestream smoke reduction via the above four mechanisms.

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A Study on the Efficiency of Smoke Barriers in the Subway Station (지하역사 제연경계벽의 제연 효용성에 관한 연구)

  • Kim, Bum-Kyu;Kim, Hee-Young;Lee, Sung-Mi;Park, Yong-Hwan
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 2008.04a
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    • pp.204-208
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    • 2008
  • Casualties Damage from Smoke is very serious consequence. Especially, Damage from smoke in in the Subway Station is the terrible result. Smoke from the fire in the Subway Station that evacuation route on the path and the sight of refugees caused by serious traffic problems. Accordingly, A study on Smoke barriers of smoke systems take into considerations relate to effects depending on wind velocity speed of the piston effect come into the retarding effect of smoke control in smoke barriers. As a result of modeling, According to increasing of Velocity in the platform which installed smoke barriers were been on the increase spreading quantity of smoke in the right direction of upstairs however, In contrast spreading quantity of smoke in the left direction on the upstairs were been on the decrease.

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Analysis of Optical Properties of Fire Smoke and Non-fire Smoke for Reduction of Nuisance Alarm (장애경보 방지를 위한 연소 연기입자와 비연소 연기입자의 광 특성 분석)

  • Jee, Seung-Wook
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.28 no.10
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    • pp.49-55
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    • 2014
  • This paper is basic study for development of an advanced photoelectric type smoke detector that has high reliability by reducing the occurrence of nuisance alarms. This paper was attempted to distinguish optical characteristics of the typical fire smoke particle and non-fire smoke particle. According to UL 268 standards, three types of test fires (the paper, the wood and the flammable liquid) were used in this paper for measurement of the fire smoke particles, and the water vapor and the cigarette smoke that were known as the main cause of the nuisance alarms were also used for the non-fire smoke particles. A smoke detection chamber was created, which was equipped with one light source and several light sensors for enabling simultaneous detection of light extinction and scattering, respectively. This paper analyzes the optical characteristics of each smoke particle using this chamber.

Effects of Platycodi Radix on Passive Smoking in Rats (간접흡연에 노출시킨 흰쥐의 폐조직 손상에 대한 길경의 보호효과)

  • Kim, Bum-Hoi
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.26 no.1
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    • pp.40-46
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    • 2012
  • Cigarette smoking is known to be associated with various chronic pulmonary and cardiovascular diseases ranging from inflammation to cancer. Not only first-hand smoke but also second-hand smoke is suggested to be a factor of health risk. This study was to investigate whether Platycodi Radix extract administration would alter oxidative stress in lung leading to protection of cigarette smoke-induced lung damage. Sprague-Dawley rats were randomly divided into 3 groups; Intact, Smoke+PR and Smoke+Vehicle. In Smoke+PR and Smoke+Vehicle group, the exposure to cigarette smoke was performed for 15 min/day for 4 weeks in ventilated smoking chamber. The Platycodi Radix extract and saline were orally administrated to Smoke+PR and Smoke+Vehicle group each. The rats of Intact group were just kept in ventilated chamber without cigarette smoke. After the experiment for 4 weeks, the lung tissues were collected for histological observation and immunohistochemistry. In Results, airspace enlargement and goblet cell hyperplasia were observed after 4 weeks' exposure to cigarette smoke. Whereas, the oral administration of Platycodi Radix extract for 4 weeks reduced airspace enlargement and goblet cell hyperplasia. Moreover, the alterations of BAX/Bcl-2 proteins in lung tissues were observed. These results suggest that Platycodi Radix extract ameliorates lung damage in cigarette smoke-exposed rats and has protective effects on second-hand smoke injury.

연기와 연기감지기술에 대한 고찰

  • Lee, Bok-Yeong
    • Fire Protection Technology
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    • s.15
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    • pp.28-38
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    • 1993
  • This report is explain the nature of smoke and the principle of smoke detection. The object of this research is to understand the hazard of smoke and select the optimum smoke detectors, according to the types of smoke and the particle size of smoke produced by fire

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PERFORMANCE EVALUATION OF PASSENGERS' EVACUATION FOR SMOKE-CONTROL MODES IN A SUBWAY STATION (지하역사 제연모드 승객피난 성능평가)

  • Park, Won-Hee;Chang, Hee-Chul;Jung, Woo-Sung;Lee, Han-Su
    • Journal of computational fluids engineering
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    • v.13 no.4
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    • pp.8-12
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    • 2008
  • Heat/smoke detectors are installed in most subway platforms in Korea to detect fire. Subway platform is divided by smoke-control zones for efficient smoke-control. Once the detectors detect heat or smoke, the smoke-control ventilation system in the platform and concourse is activated according to the smoke-control ventilation mode. Smoke-control mode during fires in Korean subway platforms is that the smoke zones operate by exhausting smoke while other zones in the platform and in the concourse which is the upper floor of the platform operate by supplying air or stopping any ventilation. This study is conducted to evaluate performance of passengers' evacuation for various smoke control modes in the subway station. Distribution of smoke and heat due to fire on the platform is analyzed by using Fire Dynamics Simulator(FDS V 4.06) of NIST. Various smoke-control ventilation modes and locations of fire are considered. Evacuation and movement of passengers within the platform is simulated by building EXODUS V.4.0.

Video smoke detection with block DNCNN and visual change image

  • Liu, Tong;Cheng, Jianghua;Yuan, Zhimin;Hua, Honghu;Zhao, Kangcheng
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.14 no.9
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    • pp.3712-3729
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    • 2020
  • Smoke detection is helpful for early fire detection. With its large coverage area and low cost, vision-based smoke detection technology is the main research direction of outdoor smoke detection. We propose a two-stage smoke detection method combined with block Deep Normalization and Convolutional Neural Network (DNCNN) and visual change image. In the first stage, each suspected smoke region is detected from each frame of the images by using block DNCNN. According to the physical characteristics of smoke diffusion, a concept of visual change image is put forward in this paper, which is constructed by the video motion change state of the suspected smoke regions, and can describe the physical diffusion characteristics of smoke in the time and space domains. In the second stage, the Support Vector Machine (SVM) classifier is used to classify the Histogram of Oriented Gradients (HOG) features of visual change images of the suspected smoke regions, in this way to reduce the false alarm caused by the smoke-like objects such as cloud and fog. Simulation experiments are carried out on two public datasets of smoke. Results show that the accuracy and recall rate of smoke detection are high, and the false alarm rate is much lower than that of other comparison methods.

Performance Evaluation of Passengers' Evacuation for Smoke-Control Modes in a Subway Station Based on CFD Results (전산열유체 해석결과를 이용한 지하역사 제연모드 승객피난 성능평가)

  • Park, Won-Hee;Jang, Yong-Jun;Lee, Han-Su;Chang, Hee-Chul;Lee, Duck-Hee
    • 한국전산유체공학회:학술대회논문집
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    • 2008.03b
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    • pp.276-279
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    • 2008
  • Heat/smoke detectors are installed in most subway platforms in Korea to detect fire. Subway platform is divided by smoke-control zones for efficient smoke-control. Once the detectors detect heat or smoke, the smoke-control ventilation system in the platform and concourse is activated according to the smoke-control ventilation mode. Smoke-control mode during fires in Korean subway platforms is that the smoke zones operate by exhausting smoke while other zones in the platform and in the concourse which is the upper floor of the platform operate by supplying air or stopping any ventilation. This study is conducted to evaluate performance of passengers' evacuation for various smoke control modes in the subway station. Distribution of smoke and heat due to fire on the platform is analyzed by using Fire Dynamics Simulator(FDS V 4.06) of NIST. Various smoke-control ventilation modes and locations of fire are considered. Evacuation and movement of passengers within the platform is simulated by buildingEXODUS V 4.0.

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