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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
141

Beliefs and behaviors related to environmental tobacco smoke (ETS) exposure in the home : cultural differences between francophones and the rest of the Canadian population

Zhu, Tong 03 January 2006 (has links)
This study explored how cultural heritage might affect peoples beliefs, attitudes, and behaviors toward Environmental Tobacco Smoke (ETS), which in turn affected actual ETS exposure. It used data from the 2001 National Survey on Environmental Tobacco Smoke in the Home. It compared two cultural groups: Francophones and the rest of the Canadian population (RCP), and found that Francophone nonsmokers had a significantly higher ETS exposure than the RCP (19.3% vs. 8.5%). The difference was much greater than the difference in smoking prevalence for the two groups (26.2% vs. 22.4%). </p>The study found Francophones scored lower than the RCP in almost every aspect of ETS-related beliefs, attitudes, and behaviors. They were less likely to believe ETS to be harmful and less supportive of ETS-control policies. They were less likely to have done something that reduced ETS exposure at home. In both cultural groups, smokers scored lower than nonsmokers in ETS-related beliefs and attitudes. However, the difference between the two groups remained significant even if the comparisons were done within smokers and nonsmokers. </p>The most significant finding of the study was that Francophones were more likely to trust those so-called ETS-reduction strategies that appeared to be effective but were not in reality (e.g., opening the window when someone smokes). Moreover, there was a statistically significant interaction between smoking status and cultural heritage: fewer nonsmokers than smokers within each cultural group believed that these strategies were really effective, but the difference between the nonsmokers and smokers was significantly smaller for Francophones than that for the RCP. Therefore, the tendency to trust ineffective ETS-reduction strategies, especially among the nonsmokers, explained why Francophones were significantly less likely to adopt strategies that would actually reduce ETS exposure. </p>These results suggest that in order to move ETS policies forward and to effectively reduce ETS exposure among Canadian nonsmokers, the key strategy is to mobilize the nonsmokers to be less tolerant of ETS and more persistent in only allowing smoking to occur outdoors. This will not only help protect nonsmokers from the harm of ETS, but will eventually help smokers to quit smoking.
142

Mechanisms of environmental tobacco smoke and benzo[a]pyrene induced cardiovascular injury and the protective role of resveratrol

Al-Dissi, Ahmad 21 March 2011 (has links)
Despite extensive research, the mechanisms behind cardiovascular effects of subchronic environmental tobacco smoke (ETS) remain unclear, but may be related to ETS-induced inflammation and oxidative stress. Additionally, the protective role of resveratrol (RES), a natural antioxidant available in red grapes, is controversial. We hypothesized that the polycyclic aromatic hydrocarbon (PAH) component of ETS is responsible for causing adverse cardiovascular effects. We also hypothesized that the administration of RES is protective against the adverse cardiovascular effects of ETS. In order to address these hypotheses, male juvenile pigs (4-weeks old) were exposed to ETS or ambient air for 28 consecutive days (1 hr/day) and effects compared to 7 days of i.v. injection of the PAH, benzo-a-pyrene (BAP; 5 mg/kg daily). In another experiment, pigs were sham-exposed or ETS-exposed, with or without oral RES treatment (5mg/kg daily). In all experiments, endothelial and left ventricular function were assessed by flow mediated dilation (FMD), and echocardiography, respectively, while blood pressure was evaluated by oscillometry. At the termination of each experiment, serum nitrotyrosine, total nitrate/nitrite (NOx) and C-reactive protein (CRP) were measured as well as hepatic and pulmonary ethoxyresorufin-o-deethylase (EROD) activity to indicate cytochrome P450 1A1 (CYP1A1) expression. Finally, the correlation between pulmonary inflammation and adverse cardiovascular effects was investigated by measuring total and differential white blood cell (WBC) count as well as leukocyte elastase activity in bronchoalveolar lavage fluid at the termination of each experiment. ETS exposure, but not BAP treatment, resulted in a significant impairment of FMD (P<0.0001) and increased left ventricular end diastolic volume (P=0.0032). Cotreatment with RES failed to restore the ETS induced impairment of FMD (P>0.05). However, a trend pointing to an increase in ejection fraction (EF) was noted (P=0.072). ETS, BAP and RES treatments failed to have any effect on blood pressure (P>0.05). BAP injection caused a significant increase in serum nitrotyrosine (P=0.0146) and CRP (P=0.012), but not serum NOx levels (P>0.05). In contrast, ETS exposure resulted in a significant increase in CRP serum levels (P=0.0092), a trend pointing to increased serum nitrotyrosine (P=0.105), and no change in serum NOx levels (P>0.05). The increased nitrotyrosine and CRP with ETS exposure was not reversed by RES administration (P>0.05). ETS exposure increased EROD activity in the lung (P=0.0093), but not the liver (P=0.12). In contrast, BAP treatment had the opposite effect (lung EROD: P=0.621, liver EROD: P=0.01), while RES administration had no effect (P>0.05). ETS exposure (P=0.0139), but not BAP treatment (P=0.723), resulted in increased WBC count in BAL fluid which was not affected by RES administration (P>0.05). These results show that ETS exposure causes lung inflammation, systemic inflammation, oxidative stress-mediated inactivation of nitric oxide and impaired endothelial function. In contrast, BAP failed to alter endothelial function, downstream of the lung, despite systemic inflammation and increased oxidative stress. Furthermore, RES failed to restore endothelial function, or decrease systemic inflammation and oxidative stress. Taken together, these results suggest either that pulmonary inflammatory responses or pulmonary increases in CYP1A1 activity may be more important links to endothelial dysfunction than systemic inflammation and nitric oxide bioactivity. The beneficial effects of RES by itself are manifested only at the cardiac level by improving the ejection fraction, but the work in this thesis failed to detect any ability of RES to ameliorate ETS cardiovascular effects.
143

A study of certain factors affecting the filtration of smoke by fibrous materials.

Perot, Jules J. (Jules Joseph) 01 January 1943 (has links)
No description available.
144

Investigation into the Emissions and Efficiency of Low Temperature Diesel Combustion

Knight, Bryan Michael 2010 August 1900 (has links)
As global focus shifts towards the health and conservation of the planet, greater importance is placed upon the hazardous emissions of our fossil fuels, as well as their finite supply. These two areas remain intense topics of research in order to reduce green house gas emissions and increase the fuel efficiency of our vehicles. A particular solution to this problem is the diesel engine, with its inherently fuel-lean combustion, which gives rise to low CO2 production and higher efficiencies than its gasoline counterpart. Diesel engines, however, typically exhibit higher nitrogen oxides (NOx [NOx = NO NO2, where NO is nitric oxide and NO2 is nitrogen dioxide]) and soot. There exists the possibility to simultaneously reduce both emissions with the application of low temperature diesel combustion (LTC). While exhibiting great characteristics in simultaneous reductions in nitrogen oxides and soot, LTC faces challenges with higher carbon monoxide (CO) and hydrocarbon (HC) emissions, as well as penalties in fuel efficiency. The following study examines the characteristics of LTC which contribute to the differences in emissions and efficiency compared to typical conventional diesel combustion. More specifically, key engine parameters which are used to enable LTC, such as EGR and fuel pressure are swept through a full range to determine their effects on each combustion regime. Analysis will focus on comparing both combustion regimes to determine how exhaust gas recirculation (EGR) and fuel pressure relate to lowering NO and smoke concentrations, and how these relate to a penalty in fuel efficiency. This study finds that the application of LTC is able to realize a 99 percent reduction in NO while simultaneously reducing smoke by 17 percent compared to the conventional combustion counterpart. Through a sweep increasing EGR, LTC is able to defeat the typical soot – NO tradeoff; however, brake fuel conversion efficiency decreases 6.8 percent for LTC, while conventional combustion realizes a 4 percent increase in efficiency. The sweep of increasing fuel pressure confirms typical increases in NO and decreases in smoke for both LTC and conventional combustion; however, brake fuel conversion efficiency increases 2.3 percent for LTC and drops 4 percent for conventional combustion.
145

The Analysis of performance-based smoke management and egress system in new-type MRT station

Chen, Jung-Chin 05 July 2001 (has links)
Recently, several major incidents occurred in worldwide metro and subway systems due to inadequate or inappropriate emergency procedures. In this study, the traditional and innovative metro underground stations were analyzed utilizity the CFAST and FDS computer program. A comparative study has been conducted to evaluate the smoke descending rate, and temperature distribution, etc with addressable zoned smoke control system. Dynamic egress analysis was followed to validate the NFPA 130 which was taken as the design guidelines to evaluate the evacuation time using SIMULEX program. Finally, the smoke management design and egress system was integrated, which warrants its qpplication in actual engineering designs.
146

Design Analysis and Experimental Investigation of Smoke Management and Egress System of a Large Shopping Mall

Yang, Chih-Sheng 30 April 2003 (has links)
ABSTRACT Almost people hurt or die because of heavy smoke when the building fires. Smoke Management is to keep the smoke in the limited zone or to change its direction and to keep the ways which the people escape bright. It is convenient for fireman to save them and to keep their life and to reduce the money loss. In the developed country of the world, smoke management design is one of the most important factors to affect egress system of the building. Effective smoke management design is to avoid the smoke diffusing or descending and to make the people have enough time to escape. The combination of smoke management and egress system using performance-based fire safety design should be developed safely and economically. In Taiwan,we haven¡¦t the proper law of smoke management and egress system about the atria of the large space. So we must progress the computer simulation about smoke management and egress system and then use full-scale experiment to perform. The major terms of the content are: 1.the optimal distribution zone analysis of smoke management of the building. 2.to design and to analyze smoke management of the atria. 3.the combination of design analysis of smoke management and egress system. 4.full-scale experimental investigation. We hope that the performance-based fire safety design method about smoke management and egress system of the large shopping mall could be the excellent model and enchance the safety of the building in Taiwan.
147

Assessment of vehicle fire development in road tunnels for smoke control ventilation design : a thesis submitted in partial fulfilment of the requirements for the Ph. D. degree in Fire Engineering, Department of Civil and Natural Resources Engineering, University of Canterbury /

Cheong, Mun Kit. January 2009 (has links)
Thesis (Ph. D.)--University of Canterbury, 2009. / Typescript (photocopy). "August 2009." Includes bibliographical references (leaves 279-296). Also available via the World Wide Web.
148

Involvement of 5-lipoxygenase in the promotion of colonic tumorigenesis by cigarette smoke

Ye, Yini. January 2004 (has links)
published_or_final_version / abstract / toc / Pharmacology / Doctoral / Doctor of Philosophy
149

A study on the ulcerogenic mechanisms of cigarette smoke exposure on ethanol-induced gastric mucosal damage in rats

周業全, Chow, Yip-chuen. January 1997 (has links)
published_or_final_version / Pharmacology / Doctoral / Doctor of Philosophy
150

Design fires in underground hard rock mines

Hansen, Rickard January 2011 (has links)
During several decades considerable research activities have been conducted with respect to fires in coal mines, but the research activities with respect to hard rock mines have been limited. As the hard rock mines are getting more complex the need for deeper understanding of fires in underground hard rock mines are getting more in demand. The more urgent demands are the need for more specific heat release rate curves as design fires, applicable fire experiments and any method that would allow for the calculation of the total heat release rate curve of an object. This thesis presents a number of examples on design fire curves applicable to underground hard rock mines; it also presents the results of model scale fire experiments and methods for calculating the total heat release rate of several objects at uniform as well as non-uniform conditions. Tests were carried out in a model scale tunnel using wooden pallets as fire load. The parameters tested were the distance between piles of pallets and longitudinal ventilation rate. It was found that an increasing ventilation rate also increases the peak heat release rate. When studying the curves of heat release rates it was found that when the distance between the ignited pile and the second pile increased to a certain level the delayed ignition of the second pile will result in that the peak heat release rate of the adjacent piles will not occur simultaneously. The ignition data indicated that the ignition time of adjacent piles decreased as the longitudinal ventilation increased.  A method using a critical heat flux as ignition criterion exhibited very good agreement with the corresponding experiments for both uniform as well as non-uniform conditions. The methods using the ignition temperature as ignition criterion did not agree very well with any of the corresponding experiments. / GRUVAN

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