Time variations of soiling index at three locations in central Montreal are analysed. The average week end reduction in smoke is about 20 percent. Readings adjacent to Mount Royal Park are reduced by nearly one half, but no attempt is made to separate out the effects of the Park acting as a smokeless zone, and the mountain acting as an obstacle to the wind flow. Data from the elevated location, together with visual observations, suggests that at night the smoke over the city is usually confined to a layer several hundred feet deep. A simple model is developed to consider the modification of stable air as it moves across a city acting as a heat and smoke source. An adiabatic mixing layer of increasing depth builds up due to the accumulation of heat. Applying this model indicates that half of the smoke in mid-winter is due to heating of buildings.

No description available.

The three research studies included in this dissertation aimed to examine the reasons for e-cigarette use among U.S. adults, and to examine the U.S. public opinion on allowing e-cigarette use where smoking is otherwise prohibited. Mixed (quantitative and qualitative) research methods were used. Data from an online survey (2012) and focus groups (2014) were analyzed. Among 307 survey respondents who had ever used e-cigarettes, the three most common reasons for e-cigarette use were curiosity (40.8%), the belief that “it helps people quit smoking” (19.1%), and perceiving e-cigarettes “less harmful than regular cigarettes” (9.3%). About 40% of U.S. adults were uncertain whether e-cigarette use should be allowed in smoke-free public areas, 37% opposed, while 23% favored allowing their use in smoke-free environments. The majority of the focus group participants have used e-cigarettes to complement regular cigarette smoking and intake nicotine where smoking is restricted. E-cigarette use was viewed to be less harmful and more convenient than smoking regular cigarettes. The findings of the three studies suggest that curiosity about e-cigarettes lead to experimentation and the convenience to use e-cigarettes in smoke-free areas lead to continual use. With impending regulation and the changing e-cigarette landscape, there is a need for continued monitoring and research on reasons for and attitudes about e-cigarette use, and on public opinion pertaining to e-cigarette use in smoke-free areas.

The goal of this study is to assess the potential of using bench-scale fire testing to screen materials for the Steiner tunnel fire test. It is hypothesized that the chemical and physical changes made to a material to improve its fire performance in small scale fire tests will have a predictable response in the Steiner tunnel. This hypothesis is based on the observation that fire test results can, in some cases, provide insight on a material's relative fire hazard, and the assumption that the relative hazard should be consistent across scale. The ASTM E84 Steiner tunnel test provides a relative ranking of material hazard in two categories. The horizontal Flame Spread Index (FSI) is used to rank the flame hazard of a material, and the Smoke Developed Index (SDI) is used to rank the smoke hazard of a material. Two fire tests are proposed to independently assess each hazard at the bench-scale. The ASTM E1354 cone calorimeter test measures a material's open-flaming heat release rate; it is proposed that the cone calorimeter test can be used to assess a material's relative flame hazard. The ISO 5659-2 smoke density chamber test measures a material's closed-environment smoke development; it is proposed that the smoke density chamber test can be used to assess a material's relative smoke hazard. The material selected for this study is fire-retarded sprayed polyurethane foam (FRSPF) insulation. Specific details of the foam chemistry, fire retardants, and the manufacturer are confidential. Generally, the foam can be described as medium-density (approximately 2 lbs/ft³), closed-celled, and semi-rigid. The fire retardant additives are comprised of differing ratios and concentrations of phosphorous- and halogen-containing compounds. A series of 30 Steiner tunnel tests is conducted on 20 different formulations. Repeated testing is conducted on several formulations in order to assess variability in the Steiner tunnel test results. Cone calorimeter and smoke density chamber tests are conducted on a subset of those formulations, in sets of 3-5 tests per formulation. Key performance indicators are identified from each fire test, relationships between those indicators are examined, and correlations are presented where strong relationships are apparent. Empirical prediction models are proposed for FSI and SDI based on the success rate of prediction, and minimization of error between experimental (measured) and modelled (predicted) results. It is concluded that for the materials tested in this study, there is sufficient evidence of consistency in relative performance to recommend bench-scale screening tests as a cost-effective alternative to repeated Steiner tunnel testing.

Research Doctorate - Doctor of Philosophy (PhD) / Airway inflammation is a key feature of asthma. Currently, airway inflammation can be detected through both invasive and non- invasive methods. Non invasive methods are safe, feasible and a potentially useful way to assess airway inflammatory markers in both healthy children and children with asthma. In this thesis, a variety of non-invasive markers (induced sputum, exhaled nitric oxide, and exhaled breath condensate) was used to investigate childhood asthma. The aim of the first study was to compare and contrast the different airway markers between healthy children and children with asthma. The second study described the different airway inflammatory phenotypes in children with asthma, and examined clinical predictors of these phenotypes; whereas the third study investigated the effects of environmental tobacco smoke (ETS) exposure on airway inflammation in childhood asthma. The final study assessed the knowledge and attitudes of parents of children with asthma towards passive smoking. The studies used both cross- sectional and longitudinal designs. Children with stable asthma aged between 7 - 17 years underwent clinical assessment, spirometry, exhaled nitric oxide (FeNO), exhaled breath condensate and sputum induction. Urinary cotinine was assayed to assess tobacco smoke exposure. These studies have found that children with asthma show differences in both clinical pattern and pathological pattern compared to healthy children. These differences were apparent with elevated FeNO and sputum eosinophils. In children with asthma, there was heterogeneity of airway inflammation. There were 2 stable inflammatory patterns: eosinophilic asthma and paucigranulocytic asthma. Unlike adult asthma, these phenotypes have different clinical features, which may facilitate detection of the phenotypes in clinical practice. ETS exposure in children with asthma was common and associated with a non- eosinophilic pattern of airway inflammation. In children who had a change in ETS exposure, sputum eosinophils were decreased whereas sputum neutrophils were increased during ETS exposure compared to a non- ETS exposure period. Fractional exhaled nitric oxide levels were decreased after exposure to ETS compared to those at the time of non- ETS exposure. The severity of asthma was increased in children living with parents who smoked. As a result, parents of children with asthma, especially smoking parents should be more aware about the harmful effects of smoking on their children’s health and themselves. Health risk awareness about tobacco smoke helps parental smokers alter their smoking behavior as well as protecting children from ETS exposure. In conclusion, the important findings of this thesis are the description of the inflammatory phenotypes in childhood asthma, the identification of clinical predictors of these phenotypes and the determination of the effects of ETS exposure on airway inflammatory patterns in childhood asthma. These results should facilitate understanding and management of childhood asthma and prompt treatment studies based on markers of airway inflammation.

Thesis (M.S.) -- Worcester Polytechnic Institute. / Keywords: Hot smoke test; FDS; CFD; Computer modelling. Includes bibliographical references (p.105-110).

Thesis (Ph. D.)--University of Washington, 1994. / Vita. Includes bibliographical references (leaves [187]-199).

Thesis (Ph. D.)--University of Hong Kong, 1999. / Includes bibliographical references (leaves 195-206).

Thesis (M.S.)--Michigan State University. Dept. of Geography, 2008. / Title from PDF t.p. (viewed on Aug. 11, 2009) Includes bibliographical references (p. 108-112). Also issued in print.

Thesis (M.S. in Meteorology)--Naval Postgraduate School, March 2005. / Thesis Advisor(s): Philip A. Durkee. Includes bibliographical references (p. 77-78). Also available online.