Thesis (MPH.) -- University of Limpopo, 2016. / Introduction: Annually, hundred thousands of people worldwide die as a result of second hand smoke (SHS) exposure. There is no safe exposure level to SHS yet in Bulawayo, smokers have been observed smoking without restraint thus exposing non-smokers to SHS. The purpose of this study was to establish the prevalence and contributing factors of SHS exposure among adults in Bulawayo, Zimbabwe. Methods: A cross sectional study was conducted and participants were randomly selected from residents who visited the 13 municipal revenue halls. A structured questionnaire was used to collect data from respondents. Descriptive and multivariate logistic regression analyses were performed. Results: Home SHS exposure prevalence was 22% and females were 2.11 times more likely than males to be exposed at home. Prevalence of SHS exposure in public transportation, health facilities, educational and food premises was 40.9%, 26.3%, 42,9% and 36.8% respectively. Conclusion: SHS exposure in Bulawayo was high and there is need to reduce SHS exposure to non-smoking adults. Keywords: Second hand smoke (SHS), Bulawayo, Prevalence, Exposure, Adult

Some metals and metalloids make significant contributions to the harmful effects of tobacco consumption although understanding the mechanisms involved in toxicity is hampered by the lack of information on their chemical and valence species, both in tobacco and in smoke. This research addresses the speciation of the metals and metalloids most frequently implicated, particularly those elements that exist in nature in multiple valence states, namely arsenic (As) and chromium (Cr), there being considerable differences in toxicity with oxidation state. A strategy was devised to overcome some of the problems that have thwarted earlier attempts at speciation. Firstly tobacco plants were cultivated under controlled conditions in compost burdened with high levels of metals and metalloids resulting in leaf with up to 250 µg g⁻¹ As, although Cr uptake was less successful. Secondly valence speciation even at the exceptionally low concentrations of As and Cr in smoke from unburdened tobacco was achieved with XANES analysis using the exceptionally bright Diamond synchrotron source. This revealed that combustion of tobacco has a marked effect on valence speciation with As(III), the reduced form of As, dominating (and persisting) in condensate of tobacco smoke while ash is dominated by the oxidised form, As(V). Chromium also appears to be present in smoke mainly as reduced Cr(III) species. HPLC-ICPMS analysis of arsenic indicates the dominance of inorganic over organic species (~4:1). Other metals were investigated in less detail. These findings establish that arsenic is present in smoke in its most toxic form and represents a significant risk to health. Conversely smokers appear to be exposed to the less harmful species of chromium. These results support a recent WHO report that includes As but not Cr in a list of four metals and metalloids recommended for regulation in crops and commercial products in the interests of public health.

"The construction of smoke hazard management systems in large buildings such as shopping malls, cinemas, airports and train stations are increasingly being based on performance based design. Hot smoke tests are a method of using simulated fire conditions to evaluate the functionality of the completed building and the installed systems without causing damage. The author amongst others performed hot smoke tests (HST) according to Australian Standard AS 4391 -1999 in several buildings. In some tests air temperatures, air speed and smoke optical density were recorded at several locations during the test of which two tests are reported. These were later modelled by the author using Fire Dynamic Simulator (FDS) to show that typical fire protection engineering consultant applying the computer model may reasonably predict some results comparable to a full sized simulation scenario. However, some aspects were not well predicted. The modelling was improved by the outcomes of an investigation of the relationship between fuel properties, plume temperature and dynamics, and grid sensitivity. Areas of potential further improvement were identified. This work highlighted that the conditions witnessed in a hot smoke test can provide a guide, but do not represent all aspects of a real fire or design fire scenario. Although the FDS hot smoke model predicted comparable results to the hot smoke test, whilst suitable for system design, computer modelling should never be used as a system installation certification tool. Data from hot smoke tests, if gathered cost effectively, can be a valuable resource for computer model verification."

Source: Masters Abstracts International, Volume: 47-01, page: 0343. Adviser: Stephanie McFall. Includes bibliographical references.

A smoke explosion is generally considered as a deflagration of the accumulated unburned fuel inside a closed compartment. However, the term smoke explosion has been widely misused for decades with a great deal of confusion, and very little research has been done towards this topic. The purpose of this research is to study the smoke explosion phenomenon in much more detail through the development of a fire scenario under various experimental conditions including ventilation size, fuel elevation and fuel mass, so that a more comprehensive understanding of this phenomenon can be achieved. A total of twenty experiments are carried out including both exploratory and final experiments. Thirteen experiments result in smoke explosions, among which there are five experiments result in more than one smoke explosion. A phenomenon referred as smoldering decay is observed in all experiments with smoke explosions, making it one of the precursors of the smoke explosion phenomenon. The smoldering decay is often indicated by an exponential decay of the temperature and is caused by the low oxygen concentration within the compartment. Based on the analysis, it is found that the vent size must be at least 50 mm in diameter in order for smoke explosions to occur. The fuel elevation has no influence on the occurrence of the smoke explosion. However when the fuel is placed near the ceiling, the temperature, the mass flow rate and the heat release rate are all lowered significantly. The size of the fuel also has no significant influence except for the duration of the experiment. The concentration of CO is scattered in the range of 1.9% and 4.3% when explosions occur. Hence, the accumulation of CO is considered not to be the direct cause for the smoke explosion. The triggering factor for smoke explosions is believed to be the flammable limit formed by the mixture of hydrocarbon and CO. The pressure difference caused by the explosion inside the compartment has to be at least 27 Pa for it to be considered as a smoke explosion.

No description available.

Yeung, Chun Yiu. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 53-62). / Abstracts in English and Chinese. / Abstract --- p.i / 論文摘要(Chinese Abstract) --- p.ii / Acknowledgements --- p.iii / List of Tables --- p.iv / Chapter Chapter 1: --- Introduction --- p.1 / Smoking: The greatest single preventable cause of death --- p.1 / Negative health impacts of smoking on non-smokers --- p.1 / Smoking ban in Hong Kong in 2007 --- p.2 / Lack of theory-based local smoking research --- p.3 / Self-Determination Theory --- p.4 / Extensions to current SDT research on smoking --- p.6 / Differentiating autonomous motivation in personal-relational dimension --- p.6 / Relational-interdependent self-construal and nature of autonomous motivation --- p.8 / Perceived competence and condition-specific self-efficacy --- p.9 / Proposed framework --- p.10 / Research purpose --- p.11 / Hypotheses --- p.11 / Statistical analyses --- p.12 / Chapter Chapter 2: --- Method --- p.14 / Recruitment strategies --- p.14 / Attrition of participants --- p.16 / Instruments --- p.16 / Variables of smoking pattern --- p.21 / Chapter Chapter 3: --- Results --- p.24 / Characteristics of participants --- p.24 / Attrition analysis --- p.25 / Descriptive statistics and construct score change from baseline to T2 assessment --- p.27 / Correlation analysis --- p.28 / Logistic regression for predicting quitters and non-quitters --- p.31 / Logistic regression for comparing the fundamental SDT and extended theoretical framework --- p.32 / Exploring the interaction effects between SDT variables and RISC in the prediction of quitting --- p.33 / ANOVAs on major variables for smokers with different quitting progress --- p.33 / "Additional analyses examining the differences in self-efficacy among quitters, quit attempters, and recalcitrant smokers" --- p.36 / Chapter Chapter 4: --- Discussion --- p.38 / Autonomous motivation and smoking cessation --- p.38 / Dilemma among health concerns and quitting behaviors --- p.39 / Possible priming effects in smoking cessation counseling sessions --- p.40 / Discrepancies in research design between the present study and previous SDT studies --- p.41 / Reflecting on the SDT and stages of health behavioral change --- p.42 / Findings related to proposed theoretical extensions --- p.43 / Relational autonomous motivation and RISC --- p.43 / Role of self-efficacy in smoking cessation: inspirations from process models of health behaviors --- p.44 / Recalcitrant smokers and their self-efficacy to respond to internal tempting conditions --- p.46 / Quit attempters and their self-efficacy to respond to external tempting conditions --- p.47 / Research limitations --- p.48 / Future directions and recommendations --- p.49 / References --- p.53

Imagens desenhadas com fuligem de fumaça sobre lâminas de vidro transparente, cujo conjunto sugere imagem em volume / Drawings with smoke dust on glass blades set suggesting volume

Imagens desenhadas com fuligem de fumaça sobre lâminas de vidro transparente, cujo conjunto sugere imagem em volume / Drawings with smoke dust on glass blades set suggesting volume

Marihuana continues to be a controversial topic in todays society. The plant material is used recreationally as a stupefacient and has a purported medicinal use. In fact, anecdotal information about its medicinal properties has been such that Health Canada has recently started an initiative to provide a well characterized supply of plant tissue to researchers interested in examining its potential medicinal properties. Simultaneously this same material is being provided for those subjects who are licensed to use marihuana as a medicine. <p>In order to further study marihuana and its component cannabinoids it is essential to be able to discern both the cannabinoid content in the product being supplied and more importantly the cannabinoid profile in the delivery system. At present the most common route of administration is via inhalation of the combusted plant material. Consequently methods capable of measuring the cannabinoid content in combusted plant material would be very useful in order to make meaningful study of the pharmacokinetics of the cannabinoids delivered by this route. <p>Investigations were carried out to develop a method and study the volatile constituents of combusted marihuana plant material in a semi-enclosed environment. Thus the hypothesis of this research is that qualitative and quantitative information can be obtained from the combustion products of cannabis plant tissue. The method relies upon the solid phase extraction of smoke arising from the combustion of plant material in a variety of combustion chambers. The combustion chambers were designed to reflect the current marihuana paraphernalia in use as well as a high efficiency in vitro system. Both the qualitative and quantitative levels of a limited number of cannabinoids were evaluated before and after combustion. A quantitative Liquid Chromatography Ultra Violet (LC-UV) detector method was validated for the analysis of a selected group of cannabinoids ( Δ9-tetrahydrocannabinol (THC), cannabinol (CBN), cannabidiol (CBD) and tetrahydrocannabinolic acid (THCA) . When this method was applied to plant material available through the medical marijuana initiative the following observations were made on the combustion products:<p> <table style="text-align: left; width: 397px;" border="1" cellpadding="2" cellspacing="2"> <tbody> <tr> <td style="width: 119px;">Material</td> <td style="width: 59px;">CBD</td> <td style="width: 59px;">CBN</td> <td style="width: 59px;">THC</td> <td style="width: 59px;">THCA</td> </tr> <tr> <td style="width: 119px;">Analyzed</td> <td style="width: 59px;">(ug/ml)</td> <td style="width: 59px;">(ug/ml)</td> <td style="width: 59px;">(ug/ml)</td> <td style="width: 59px;">(ug/ml)</td> </tr> <tr> <td style="width: 119px;">Plant</td> <td style="width: 59px;">BLQ</td> <td style="width: 59px;">BLQ</td> <td style="width: 59px;">BLQ</td> <td style="width: 59px;">890</td> </tr> <tr> <td style="width: 119px;">Combusted</td> <td style="width: 59px;">20</td> <td style="width: 59px;">14</td> <td style="width: 59px;">420</td> <td style="width: 59px;">28</td> </tr> </tbody> </table> 5 mg plant tissue extracted using a validated HPLC-UV method <p> 5 mg plant tissue combusted in a closed combustion chamber.<p> BLQ: below level of quantification (<12.5 ug/mL)<p>These results sparked further research into the quantitative transformation of cannabinoids during the combustion process. In this regard, it was shown that THC, CBD and CBN all could be recovered at approximately a 90% ratio upon combustion However, THCA was thermally converted such that very little remains after combustion and furthermore, its degradation product, THC can only account for 50% of the THCA. The latter observation is important since there has been a prevailing thought that THCA is quantitatively transformed during combustion to THC while in fact this transformation is approximately 50%. This finding must be considered when pharmacokinetic studies are carried out using inhalation of combusted plant material as the delivery system.<p>A further finding of this research is that not all popular combustion devices yield identical quantitative cannabinoid profiles. In this regard, the simpler pipe systems result in the highest yields of heat transformed cannabinoids while the vaporizer systems have the lowest cannabinoid yields.