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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.
101

A STUDY ON THE BIOCHEMICAL AND CELLULAR EFFECTS OF ENVIORMENTAL TOBACCO SMOKE ON ADULT AND DEVELOPING RAT BRAIN BIOCHEMISTRY

Fuller, Brian 01 January 2011 (has links)
Exposure to environmental tobacco smoke (ETS) has been recognized as a significant health risk for adults and children. In adults, ETS exposure has been linked to increased incidences of cardiovascular disease and dementia. In children, exposure has been linked to behavioral and cognitive deficits. Studies on the effects of ETS in the brain have been largely epidemiological, and have lacked a defined explanation of the molecular/biochemical effects of ETS. The present dissertation aims to test whether ETS exposure leads to altered biochemistry in the adult and developing mammalian brain. A rat ETS exposure model was employed to investigate changes at the molecular and cellular level. In an adult ETS exposure study, we focused on markers of astrogliosis , oxidative stress, and cell death. We observed altered GFAP suggestive of reactive astrogliosis. Yet, markers of oxidative and cell stress were unaffected by ETS exposure in the brain regions examined. Increased degradation of αII-spectrin and dephosphorylation of serine116 on PEA-15 indicated greater apoptotic cell death signaling in the brains of ETS exposed animals. β-synuclein was greatly upregulated by ETS, a neuroprotective protein previously reported to exhibit anti-apoptotic and anti-fibrillogenic properties. We next employed a rodent model of postnatal ETS exposure to investigate effects on developing cerebellum using a system biology approach involving mass spectrometry (MS). Proteins at statistically different abundance between groups were correlated with relevant biochemical processes and pathways by bioinformatics. ETS responsive data were enriched in elements associated with all aspects of aerobic respiration. These results were substantiated by orthogonal molecular measures, along with evidence for increase mitochondrial biogenesis/fission. These findings suggest an increase mitochondrial density driven by a demand for ATP. Further exploration of the ETS responsive proteome identified statistically significant associations of the ETS with neuron projections, in particular axon associated proteins and synaptic vesicles. Immunotbloting and microscopy experiments substantiated altered process outgrowth and synaptogenic processes. The presented data depict a striking modulation in cerebellar formation consequent to ETS exposure and the energy source to allow that modulation to occur. Our findings could provide a biochemical and cellular rational for adverse neurological effects observed in ETS exposed children.
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102

A Study of Smoke Aging Examining Changes in Smoke Particulate Size

Lynch, James Andrew 10 May 2004 (has links)
The size of a soot particle has an effect on smoke detector alarm activation. It is the purpose of this paper to identify changes to soot particle size and examine if those size changes effect smoke detector alarm times in the ceiling jet. Changes in particle size has been attributed to delays in detector activation, however, little evidence exists to support that particle size changes occur in the ceiling jet where detector activation occurs. This paper presents the results from laser scattering experiments and calculations conducted to support and validate the experimental findings. The laser scattering from various aerosols was collected, over time, to examine changes in particle size due to agglomeration in the smoke aging process. The laser scattering measurements were made at two linear polarizations, vertical (VV) and horizontal (HH), and scattering angles ranging from 20 to 155 degrees. A laser with a wavelength of 632.8 nm was used as a light source. The aerosol laser scattering results were then compared to the results from the Mie scattering theory. The Mie scattering theory was adjusted using a lognormal distribution to generate theoretical light scattering curves expected from a polydisperse aerosol typical of smoke. The collected data was examined using a combination of the Mie theory with various particle sizing techniques, including dissymmetry ratio and polarization ratio, to look for changes in laser scattering indicating changes in particle size.
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103

Tenant perceptions of drifting environmental tobacco smoke in multi-unit dwellings

McCammon-Tripp, Laura E. January 2010 (has links)
Background and Objectives: Environmental tobacco smoke (ETS) is widely recognized as a serious health hazard. No safe level of exposure to ETS has been identified (USDHHS, 2006; WHO, 2007). The importance of smoke-free spaces in improving health outcomes for both smokers and non-smokers is clearly understood and as such, many individuals living in Ontario have made their homes smoke-free. Although those living in units within multi-unit dwellings (MUDs) have the option of making their own unit smoke-free, they may still be involuntarily exposed to ETS drifting from smoking units to their unit. The present study explores tenant’s perceptions of this drifting ETS and the potential market for smoke-free rental housing. Methods: Anonymous surveys were sent to 3724 households within rented MUDs (apartments and row housing) with five or more units in Kitchener, Ontario. In addition to demographic questions, the survey addressed respondents’ experiences with, perceptions of, and reactions to drifting ETS and their views on smoke-free rental housing. Three hundred and five surveys were returned, and 291 met the final inclusion criteria to be included in the analysis. Survey data were weighted by age and education level. Descriptive analyses and logistic regression models were run to answer the research questions. Results: Over half of the respondents who do not smoke in their unit on a daily basis indicated they were exposed to drifting ETS in their home at least ‘sometimes’. Of those who were exposed, 89.5% were bothered and nearly half were bothered ‘a lot’. This suggests drifting ETS is a concern for many tenants living in MUDs. The majority of tenants indicated they did not live in a smoke-free building however there was a strong interest in smoke-free rental housing. Nearly 90% of tenants showed at least some interest in smoke-free rental housing, and many tenants would prefer to live in a building with the strongest possible restrictions on smoking in place. Younger tenants, non-smokers, those who spent less time at home on weekends and those who perceived indoor smoking as a fire risk were more likely to be interested in smoke-free rental housing. Conclusions and Significance: This study provides insight into the magnitude of the problem of drifting ETS in MUDs and can be used to inform policy on smoke-free MUDs. Many respondents indicated they were exposed to drifting ETS and the majority of those who were exposed were bothered by this exposure. There also appears to be a strong market for smoke-free rental housing. The response rate for this study was low at 8.5% and as such the results must be interpreted with caution. Future research should be completed in other jurisdictions and with larger sample sizes. Landlord surveys and air quality monitoring studies are also needed. While additional research is needed, the current study suggests this is an important public health issue, and provides additional evidence supporting the need to explore policy options in the public and private realm for smoke-free housing.
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104

An Examination of Secondhand Smoke in a Sample of Atlanta Hospitality Venues and Their Compliance with the Georgia Smokefree Air Act

Nachamkin, Eli W 20 December 2012 (has links)
Introduction: Despite the known consequences of cigarette smoking, almost 20% of adults in the United States smoke. Smoking has been shown to harm nearly every organ of the body. Its detrimental effects have been seen not only in smokers themselves but also in those exposed to secondhand smoke (SHS) at work and in other public places. Methodology: The purpose of this thesis was to examine compliance with the signage requirement of the Georgia Smokefree Air Act (GSAA) of 2005 among 99 hospitality venues located in Atlanta. Photographs of bars and restaurant entrances were taken and raters then classified each venue as compliant or non-compliant with smoking status signage requirements of the GSAA. Additionally, air samples were collected using Sidepak equipment from 59 venues in order to estimate the PM2.5 levels, which is a recognized measure of air quality. With Spearman’s rho correlation coefficient (r), analyses were run to determine correlations between signage compliance, number of cigarettes being smoked, and smoking permitted with air quality (PM2.5). Analyses were conducted using the Statistical Package for Social Sciences (SPSS) version 19. Results: Of the 99 venues assessed, only 21 (21.2 %) complied with the signage requirements of the GSAA. Venues that do adhere to signage requirements and indicate no smoking on their signs and at the same time via telephone stated that smoking is prohibited had the lowest PM2.5 levels =15.03. On the contrary, those venues that display signs permitting smoking and via telephone indicated smoking is allowed had the highest PM2.5 levels =230.31. It was determined that there is a strong positive correlation between PM2.5 and “number of cigarettes” (r=.611, n=59, p<.001) as well as moderate correlation between PM2.5 and “smoking permitted” as indicated from phone calls (r=.464, n=59, p<.001). However, analysis showed a weak correlation between PM2.5 and “signage compliance” in accordance with GSAA (r=.107, n=59, p>.001). Conclusions: Enforcement of GSAA must be enhanced in order to better protect workers and patrons of Atlanta’s bars and restaurants from harmful exposure to SHS. Findings from this study support that prohibiting smoking in bars and restaurants and having signs stating that smoking is prohibited would improve air quality and protect workers by eliminating their exposure to SHS while working.
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105

Tenant perceptions of drifting environmental tobacco smoke in multi-unit dwellings

McCammon-Tripp, Laura E. January 2010 (has links)
Background and Objectives: Environmental tobacco smoke (ETS) is widely recognized as a serious health hazard. No safe level of exposure to ETS has been identified (USDHHS, 2006; WHO, 2007). The importance of smoke-free spaces in improving health outcomes for both smokers and non-smokers is clearly understood and as such, many individuals living in Ontario have made their homes smoke-free. Although those living in units within multi-unit dwellings (MUDs) have the option of making their own unit smoke-free, they may still be involuntarily exposed to ETS drifting from smoking units to their unit. The present study explores tenant’s perceptions of this drifting ETS and the potential market for smoke-free rental housing. Methods: Anonymous surveys were sent to 3724 households within rented MUDs (apartments and row housing) with five or more units in Kitchener, Ontario. In addition to demographic questions, the survey addressed respondents’ experiences with, perceptions of, and reactions to drifting ETS and their views on smoke-free rental housing. Three hundred and five surveys were returned, and 291 met the final inclusion criteria to be included in the analysis. Survey data were weighted by age and education level. Descriptive analyses and logistic regression models were run to answer the research questions. Results: Over half of the respondents who do not smoke in their unit on a daily basis indicated they were exposed to drifting ETS in their home at least ‘sometimes’. Of those who were exposed, 89.5% were bothered and nearly half were bothered ‘a lot’. This suggests drifting ETS is a concern for many tenants living in MUDs. The majority of tenants indicated they did not live in a smoke-free building however there was a strong interest in smoke-free rental housing. Nearly 90% of tenants showed at least some interest in smoke-free rental housing, and many tenants would prefer to live in a building with the strongest possible restrictions on smoking in place. Younger tenants, non-smokers, those who spent less time at home on weekends and those who perceived indoor smoking as a fire risk were more likely to be interested in smoke-free rental housing. Conclusions and Significance: This study provides insight into the magnitude of the problem of drifting ETS in MUDs and can be used to inform policy on smoke-free MUDs. Many respondents indicated they were exposed to drifting ETS and the majority of those who were exposed were bothered by this exposure. There also appears to be a strong market for smoke-free rental housing. The response rate for this study was low at 8.5% and as such the results must be interpreted with caution. Future research should be completed in other jurisdictions and with larger sample sizes. Landlord surveys and air quality monitoring studies are also needed. While additional research is needed, the current study suggests this is an important public health issue, and provides additional evidence supporting the need to explore policy options in the public and private realm for smoke-free housing.
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106

Fourier transform infrared spectroscopic measurement of carbon monoxide and nitric oxide in sidestream cigarette smoke in real time using a hollow waveguide gas cell and nonimaging optics

Thompson, Bruce Thomas 24 June 2004 (has links)
The application of a hollow waveguide (HW) was investigated as a gas cell for analytical infrared analysis. The analysis was the measurement of carbon monoxide (CO) and nitric oxide (NO) in sidestream cigarette smoke. An FT-IR analysis system was setup with a 3m multi-pass gas cell and a 55cm by 2mm i.d. Ag/AgI coated HW in tandem with individual CO and NO gas analyzers. The HW demonstrated response times an order of magnitude less than the larger volume multi-pass gas cell and slightly faster than the single analyte gas analyzer. Furthermore, it has been demonstrated that the HW provides up to approx. 60% greater sensitivity on a per meter optical path basis than the multi-pass gas cell of the analytes investigated due to increased optical efficiency maximizing the light concentration within the gaseous sample volume. Simulations in 3-D showed the sensitivity could theoretically improve by more than an order of magnitude if the IR beam was coupled more efficiently into the waveguide. Both FT-IR configurations gave statistically equivalent results for CO to the independent analyzers. With the HW increased temporal resolution, inter-puff measurements comparable to the gas analyzer were achieved at a lower spectral resolution. The HW optical configuration was modeled for ray tracing in MATLAB. Simulations in 2-D and 3-D were accomplished. The simulations show a major drawback to HW optimization is the coupling of the infrared beam into the waveguide. As demonstrated in a 3-D simulation, approximately 97% of the rays are rejected when an off-axis parabolic mirror with 25.4mm focal length is used to focus the IR beam into the 2mm i.d. waveguide. Repeating the simulation with longer focal length mirrors showed improved in IR coupling into the waveguide from 3% to 85%. Simulations applying a compound parabolic concentrator show comparable performance to the traditional design of two OAP mirrors to collect rays from the HW and focus onto the detector, but in a much smaller configuration. The simulation routines can be used to further improve the design of this and other optical sensing systems and enhanced by incorporating a spectral component to the simulation.
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107

Simulation of Fire in Cleanroom

Chen, Cho-Cheng 09 July 2001 (has links)
This thesis studies the following four topics by CFD simulation. First, the detailed airflow patterns and pressure characteristics of a semiconductor fab were analyzed and verified by available experimental data. Second, both transient and steady state simulations of a fire incidence were conducted to study the influences of fire source volume, fire source altitude, and clean room filter face velocity on the temperature distribution around the vicinity of fire source. Note the temperature distribution at the altitude of fire distinguisher (close to the height of ceiling) is very related to the action mechanism of fire distinguisher. Third, the mean trajectories of various particle sizes in the very early stage of a fire occurrence were simulated to provide substantial information to properly locate the VESADs (very early smoke detect active). Fourth, the performances of three commonly adopted smoke control/exhaust systems for semiconductor fabs were evaluated. An appropriate smoke control/exhaust system is provided and discussed.
108

Application and Analysis of Make-up Air Designs in Large Area Smoke Management Systems

Chio, Chia-Shien 27 June 2008 (has links)
Many large space buildings have been built in Taiwan during the past decade and people are very concerned about the fire safety inside the large space. Therefore, a performance-based smoke management system with makeup air system has been exercised. For steady flow, the mass flow of air or smoke exhaust from the top of an atrium equals the mass flow of air entering below the smoke layer. This airflow entering the atrium is referred to as makeup air, and the makeup air can be either supplied naturally or by fan power. In this research, various full-scale hot smoke tests for makeup air systems will be performed to evaluate the temperature distribution of smoke layer and the smoke descending rate at ABRI large space fire lab in Tainan. The experimental results obtained will be utilized as an important reference to establish the code of smoke management system with makeup air system in Taiwan.
109

The role of smoke as a germination cue.

Light, Marnie Elizabeth. 25 November 2013 (has links)
No abstract available. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2006.
110

Mutagenicity of cigarette smoke condensate in Neurospora crassa and Salmonella typhimurium

Demarini, David Michael. Brockman, Herman E. January 1980 (has links)
Thesis (Ph. D.)--Illinois State University, 1980. / Title from title page screen, viewed Feb. 17, 2005. Dissertation Committee: Herman Brockman (chair), Arlan Richardson, David Weber, Alan Katz, Brian Wilkinson. Includes bibliographical references (leaves 150-166) and abstract. Also available in print.

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