Thesis (M.S.)--University of Nevada, Reno, 2008. / "December, 2008." Includes bibliographical references (leaves 60-64). Online version available on the World Wide Web.

Thesis (M.App.Sc.) - Carleton University, 2007. / Includes bibliographical references (p. 159-162). Also available in electronic format on the Internet.

Thesis (Ph. D.)--University of Canterbury, 2009. / Typescript (photocopy). "Fire engineering research thesis August 2009." Includes bibliographical references (p. 411-421). Also available via the World Wide Web.

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Master of Science / Department of Food, Nutrition, Dietetics and Health / Edgar Chambers IV / Smoking of food is one of the oldest methods of food preservation and still is used widely to help preserve foods such as meats, fish and cheeses. Apart from its conservation function, the smoking process also has a considerable influence on the sensory characteristics of the products. A highly trained, skilled descriptive sensory panel identified, defined and referenced 14 attributes related to the flavor of food products labeled as smoked or smoky. The lexicon included: Smoky (Overall), Ashy, Woody, Musty/Dusty, Musty/Earthy, Burnt, Acrid, Pungent, Petroleum-Like, Creosote/Tar, Cedar, Bitter, Metallic and Sour. Definitions of these attributes were written and references were found that anchor a 0-15 point scale. This lexicon was used to evaluate the differences among smoked products under different circumstances such as products on the market versus products smoked at home, different woods used to smoke products and the length of time a product spends in the smoker. There are many methods used to impart this smoky flavor and due to health, environmental and economic concerns, many producers use nontraditional methods while hobbyists thrive on the traditional methods. Descriptive analysis was used to see if there are differences between products smoked using an at-home smoker and market products. Using principal component analysis, cluster analysis and analysis of variance, it was found that market products were significantly different than products smoked using an at home smoker. The market products were significantly more Sour and less Smoky, Ashy, Woody, Musty/Dusty and Acrid. Many types of woods are used to smoke products and many market products distinguish themselves based on the wood used. Six highly trained panelists evaluated pork that was smoked with either hickory, mesquite, cherrywood or Applewood and was smoked for 1, 2 or 4 hours. The flavor profiles of the smoke flavor was similar between the types of woods although as the length of time in the smoker increased and the intensities of most attributes rose, the differences among products smoked with different woods became more pronounced. Apple wood smoked products had higher intensities for Overall Smoky, Ashy, Burnt, Pungent, Petroleum-Like, Creosote/Tar and Cedar, while cherry wood smoked products had lower intensities for all attributes. Hickory and Mesquite smoked products were not significantly different from each other and typically scored between the other two woods. Smoking is a slow process and many popular restaurants that smoke their own products find that their claims of smoking for long periods of time are beneficial to their image. Descriptive analysis was used to see how the flavor changes based on the length of time the product (pork) was in the smoker. The samples of pork ranged from not smoked to smoked for 15 hours, with samples at every 2.5 hour increment. For most attributes, the intensities went up with the amount of time the product was in the smoker. The only exceptions were Musty/Earthy and Sour. The regression analysis revealed that Smoky, Ashy, Acrid, Creosote/Tar and Bitter are all at least moderately correlated with the time the product spent in the smoker.

This work is an experimental and theoretical analysis of factors and conditions affecting smoke and carbon monoxide (CO) production in corridor-like enclosure fires. Thirty eight experiments were performed in a three metre long corridor-like enclosure having a cross section 0.5 m x 0.5 m, door-like openings in the front panel and a propane gas burner located near the closed end. Measurements of smoke and carbon monoxide concentrations were performed at locations inside the enclosure and also in the exhaust duct of a hood collecting the combustion products. The main conclusion of this work is that smoke production depends not only on the fuel and Global Equivalence Ratio (GER) - as is reported in the literature - but also on the temperatures and residence time inside the enclosure, at least for the experimental conditions examined in this study. Additionally, it was found that the smoke concentration inside the enclosure was increasing during the ventilation controlled regime even after external burning started. Such increase was verified by temperature, smoke and velocity measurements inside the enclosure. The increase was due to reverse flow behind the flames travelling along the corridor. Namely, the gases reversed direction behind the flames with hot gases travelling in the upper layer backwards towards the closed end of the corridor in contrast to hot gas movements towards the opening in front of the flames. This recirculation was confirmed by velocity and oxygen concentration measurements in the upper and lower layers inside the enclosure. In addition, the present results show that the relationship reported in the literature between smoke and carbon monoxide production during overventilated conditions yco/ys ≈ constant, is no longer valid during an underventilated enclosure fire. The ratio yco/ys increases for the Global Equivalence Ratios of the enclosure greater than one. The obtained results are useful for CFD validation and specifically applicable for assessing smoke hazards in corridor fires in buildings where smoke concentrations can be much larger than anticipated owing to leakage to adjacent rooms behind travelling flames.

Recently, plenty of large/public buildings have been completed in Taiwan. For bright indoor environment and comfortable feelings, these buildings often utilized lots of large spaces such as atria. However, it is difficult to maintain tenable conditions within atria and large spaces in case of fire. Therefore, the alert of smoke detectors and the efficiency of smoke control systems are both very important when a fire occurred and people needed to evacuate. In large space buildings, the smoke exhaust fan and smoke storage are major design concepts of the passive smoke management systems in order to maintain tenable conditions in means of egress. In this research, the operation strategies of passive smoke management and fire detection systems in large space buildings will be systematically analyzed. The full-scale hot smoke test can be performed to evaluate the temperature distribution of smoke layer and the smoke descending rate at ABRI large space fire lab in Tainan. In the other hand, the beam detectors can not only detect smoke layer by fire more earlier but show excellent smoke rejection if they can be effectually connected with passive smoke control systems. It is anticipated that through the execution of this research project, the concept developed in this study can be applied to improve the passive smoke management performance of large space buildings in Taiwan.

In case of fire, the smoke plum will reach the roof creating a ceiling jet leading to the edge and starting to descend. The smoke descending rate depends heavily on the smoke production rate and the way it was produced. Recent research has been concentrated on the smoke produced in an axi-symmetric plume model, but rarely on wall or corner plume models. In addition, the smoke production rate was estimated based on different fire sizes, which neglected the effect introduced by the make-up air, and is the main theme of this study. During the earlier stage of this study, the calculation models to predict the smoke entrainment rate was analyzed to identify its effectiveness in calculating the smoke production rate under cornered fires. In addition, the effect of the make-up air on the mechanical and natural smoke exhaust system was analyzed to calculate the corresponding smoke descending rate. Finally, the optimal calculation model to be utilized for the performance-based fire engineering designs of smoke management systems will be proposed, so that the make-up air effect can also be coupled during the design process.

Chronic obstructive pulmonary disease (COPD) is a highly prevalent disease in the elderly. It is currently the fourth leading cause of death and will become the third by 2030. Cigarette smoke is the major cause of COPD pathogenesis, resulting from the burden of oxidants, which stimulates the production of inflammatory chemokines, leading to the influx of inflammatory cells into the airways and causing chronic inflammation. Due to lung infection by bacteria, such as Pseudomonas Aeruginosa during acute exacerbation in COPD, cigarette smoking might induce an immunosuppressive effect, which leads to bacteria colonization in the airways and further contributes to the chronic inflammation in the airway of COPD. Furthermore, cigarette smoke-induced production of reactive oxygen species (ROS) also plays an important role in the pathogenesis of COPD, however, N-acetyl-L-cysteine (NAC), which has been administered for the treatment of COPD as a mucolytic agent, also showed antioxidant and anti-inflammatory effect. The exact mechanism or cellular pathway through which cigarette smoke suppresses bacteria-induced inflammatory response and how NAC acts as an anti-inflammatory agent still remains uncertain. This study aims to investigate the effect of cigarette smoke and lipopolysaccharide (LPS) alone or in combination on the release of pro-inflammatory chemokines and to elucidate cigarette smoke-induced chemokines release in the presence and absence of NAC. Both cigarette smoke and LPS alone induced the release of interleukin-8 (IL-8) and monocyte chemoattractant protein-1 (MCP-1).Cigarette smoke suppressed the LPS-induced IL-8 and MCP-1release. NAC reduced both basal and cigarette smoke-induced secretion of these inflammatory chemokines. Moreover, Western blot demonstrated that cigarette smoke activated AMPKα phosphorylation, which was suppressed with NAC pretreatment, suggesting that NAC might have inhibitory effect on the release of chemokine release via the AMPK pathway. Our current data suggests that there may be a link between ROS generation to AMPK activation and chemokine release in BEAS-2B cells. / published_or_final_version / Pharmacology and Pharmacy / Master / Master of Medical Sciences

The design of smoke management systems for buildings such as atria, covered shopping malls and sports arenas require appropriate calculation methods to predict the volume of smoky gases produced in the event of a fire. The volume of smoke must be calculated in order to determine the required fan capacity or ventilator area for a smoke management system. In design, consideration is often given to entrainment of air into a smoke flow from a compartment opening that subsequently spills and rises into an adjacent atrium void. This type of plume is commonly known as a thermal spill plume. There has been much controversy over the validity of various entrainment calculation methods for the spill plume and there are considerable differences in the calculated smoke production rates using these methods. There are also scenarios involving the spill plume where design guidance is very limited. Whilst over-sizing of the required smoke exhaust can be uneconomical, under-sizing can compromise the design objectives. This work attempts to rigorously characterises thermal spill plume entrainment using new data obtained from an extensive series of 1/10th physical scale modelling experiments, supported by numerical modelling using Computational Fluid Dynamics. Spill plume behaviour and subsequent entrainment appears to be specifically dependent on the characteristics of the layer flow below spill edge, particularly in terms of the width and the depth of the flow. Plumes generated from narrow, deep layer flows entrain air at a greater rate with respect to height compared to plumes generated from wide, shallow layers. The findings of this work go some way to explain and reconcile differences in entrainment reported between previous studies. New guidance has been developed for the thermal spill plume in smoke management design, in the form of a range of new simplified design formulae,improvements to analytical calculation methods and an initial assessment of the use of numerical modelling using Computational Fluid Dynamics.