In South Africa one of the strongest influences on domestic indoor air quality is the type of energy used for heating, cooking and other household purposes. Emissions from fuel combustion, along with housing factors, can result in respiratory infections, a leading cause of death in the country. In this study I examine the relationships between energy types, patterns of use, housing conditions such as improper ventilation and overcrowding, indoor air quality and respiratory health in poorer communities of Msunduzi Municipality, South Africa. These variables were examined using an ecohealth perspective through the integration of data concerning individual time-activity budgets, housing materials and structure, energy sources used for heating, cooking and lighting, respiratory symptoms and continuous real time monitoring of indoor air pollutants (particulate matter (PM), carbon dioxide (CO2), carbon monoxide (CO) and sulphur dioxide (SO2)). A total of 20 dwellings, displaying large variability in housing structure and energy patterns, were sampled for 24 hours (hr) over a period of 60 days. The mean 24-hr average indoor concentrations measured were as follows: PM2.5= 16 ± 11 µg/m3, PM10= 78 ± 46 µg/m3, CO= 5 ± 6 ppm and SO2= 0.18 ± 0.27 ppm. Mean indoor concentrations measured were significantly greater than mean outdoor concentrations (p<0.0001 (PM2.5), p=0.017 (PM10), p<0.0001 (CO), p<0.0001 (SO2)). Although PM concentrations increased with the use of increasingly inefficient-burning fuel types (gas < paraffin < wood), no significant differences in the means were found across these fuel types. It is thought that the high degree of variability among dwellings and the small sample size in this study obscured any statistically significant relationships. No significant differences in mean concentrations were found across different housing types either. Indoor exposures were, on average, highest among very young children (ages 0-5) and elders (ages 51+). All age groups reported experiencing high levels of respiratory symptoms, with the elder group (ages 51+) reporting the highest percentages for each symptom. This study will be used to inform local governments and NGOs of local indoor air pollution and exposure risks, so that policy and resources can be allocated accordingly to improve physical environments. / Thesis (Master, Environmental Studies) -- Queen's University, 2007-09-27 08:52:05.443

Substituted tetrazines have been found to undergo facile inversed electron demand Diels-Alder reactions with “tunable” reaction rates. By varying the substituents on tetrazine, cycloaddition rate variations of over 200 fold have been achieved with the same dienophile. Coupled with the availability of different dienophiles, such as norbornene, the reaction rate difference can be over 14,000 folds. These substituted tetrazines can be very useful for selective labeling under different conditions. This finding paves the way to utilize tetrazine conjugation reactions for not only DNA but also stage labeling work. Carbon monoxide (CO) belongs to the gasotransmitter family of signalling molecules in the mammalian systems with importance on par with that of NO and H2S. Studies have shown that endogenous production of CO has anti-inflammatory, anti-proliferative, and anti-apoptotic effects in mammalian system. Besides of the conventional metal-based carbon monoxide releasing molecules (CORMs) to deliver CO for therapeutic purposes, organic CO prodrugs represent a new direction. Here we report the “click and release” approached to release CO. Unlike the metal-based CORMs, our system does not contain transition metal and liberates CO with controllable manner and possesses potential tunable releasing rate property under physiological conditions.

Detta arbete utfördes i syfte att analysera och utvärdera effekterna av att dosera svavel till förbränningen i en biopanna. En utrustning för detta ändamål installerades till biopannan vid fjärrvärmeverket i Arvika för att få bukt med höga halter av kolmonoxid i rökgaserna. Analysen har genomförts med avseende på hur väl svaveldoseringen uppfyller sitt tilltänkta syfte men även på eventuella bieffekter. Korrosionsrisker, halter av oförbränt svavel i rökgaser, rökgaskondensat, flyg- och bottenaska samt vad som sker kemiskt i förbränningsprocessen vid tillsats av svavel har studerats. Driftrapporter från biopannan analyserades parallellt med en informationshämtning i form av en litteraturstudie och kontakt med sakkunniga personer för att svara på ställda frågor. CO-halten i rökgaser sjunker vid tillsats av svavel. Laboratorieanalyser och driftrapporter visar på en närvaro av svavel i rökgaser, rökgaskondensat samt flyg- och bottenaska. I resultatet framgår att halterna är acceptabla. Risken att svaveltillsats i förbränningen skulle ha en negativ inverkan på korrosion i biopannan anses vara låg. Kunskapsläget om vad som sker kemiskt i förbränningsprocessen vid tillsats av svavel är bristfälligt. Fullskale- samt laboratorieförsök har genomförts utan att kunna påvisa exakt hur svavlet sänker CO-halterna i rökgaser.Nyckelord / This study was performed in order to analyze and evaluate the effects of dosing sulfur to the combustion process in a bio fueled boiler. Equipment for this purpose was installed to the bio boiler at a district heating plant in Arvika in order to overcome high levels of carbon monoxide in the flue gas. The analysis has been carried out with regard to how well the sulfur dosage is fulfilling its intended purpose but also to possible side effects. Corrosion risks, levels of unburned sulfur in flue gas, flue gas condensate, air and bottom ash along with what happens chemically in the combustion process have been studied. Operational reports from the bio fueled boiler was studied and analyzed. To find out other effects of adding sulfur to the combustion a literature study was performed as well as direct contact with experts on the subject. CO content in the flue gas drops when adding sulfur to the combustion process. Laboratory analysis and operational reports indicate a presence of sulfur in the flue gas, flue gas condensate and fly ash and bottom ash. The results show that the levels are acceptable. The risk of causing corrosion in the plant by adding sulfur to the combustion is considered low. The current knowledge of what is happening chemically in the combustion process by the addition of sulfur is insufficient. Full-scale and laboratory experiments have been carried out without being able to show exactly how the sulfur lowers CO concentrations in flue gases.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2007. / Härtill 5 uppsatser.

Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 216-224).

Thesis (Ph. D.)--University of Texas at Austin, 2007. / Vita. Includes bibliographical references.

Thesis (Ph. D.)--University of Washington, 2004. / Vita. Includes bibliographical references (leaves 196-214).

Thesis (M.S.)--West Virginia University, 2000. / Title from document title page. Document formatted into pages; contains xvi, 129 p. : ill. Includes abstract. Includes bibliographical references (p. 78-82).

Thesis (Ph. D.)--Ohio State University, 2006. / Title from first page of PDF file. Includes bibliographical references (p. 126-130).

Thesis (Ph. D.)--University of Washington, 2005. / Vita. Includes bibliographical references (leaves 99-120).