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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.
161

Multiple Sclerosis Disease Distribution and Potential Impact of Environmental Air Pollutants in Georgia

Gregory, Anthony Charles 23 July 2007 (has links)
This study’s purpose is to examine the potential relationships between MS (Multiple Sclerosis) and environmental outdoor air pollutants in GA (Georgia). We used secondary, cross-sectional data received from the member’s list of the National Multiples Sclerosis Society’s GA chapter (NMSS-GA), the U.S. census, and scorecard.org, a database based on the U.S. Environmental Protection Agency (EPA) Toxic Release Inventory (to 2002) and National Emissions Inventory (1999) data. The study population was 9,072,576 including 6,247 self-reported MS cases from NMSS-GA. Using stepwise multivariate linear regression of census and EPA data, the best predictive model in GA for female or total prevalence rates used per capita income and coarse particles (PM-10); male prevalence rates included only per capita income. The relationship between MS and PM-10 could be facilitated by influences of PM-10 on the systemic immune response and inflammation. More exposure and basic and clinical research are needed to understand environmental influences on MS.
162

Evaluation on Health Impact of Government Support for GER (Traditional Dwelling) District's Electricity Night Rates in Ulaanbaatar City

Nansalmaa, Erdenekhuu 07 May 2011 (has links)
During the last 10 years, air pollution has become one of the major public health problems in Ulaanbaatar city of Mongolia, and concentrations of pollutants were measured 3 to 50 times higher than WHO recommendation. This devastating air pollution is produced mostly by thousands of families who migrated from countryside and live in gers (traditional dwellings) in the suburban area which is not connected to the central heating system, and nearly all of them burn coal to keep them warm. Due to air pollution, residents living in Ulaanbaatar city suffer health problems that equal to the smoking of 4-5 packs of cigarettes. During the winter time, PM10 hourly average concentrations increased to 2,300 μg/m3, and daily average became over than 1,000 μg/m3 in the most polluted parts of the city. At present, Mongolian government has accepted that the health of Mongolian residents has deteriorated at an alarming level. In January of 2011, Mongolian Parliament approved the Law on Reduction of Air Pollution in the Capital City to control air pollution and eliminate the gaps in practice. One main provision of this law was to improve ger district electricity transmission and distribution network and reduce the night-time price of electricity by 50 percent. Therefore, this study aimed to estimate direct health benefits of Government Provision on cutting electricity payment by 50 percent during the night time and analyze the efficiency of this program on reducing air pollution and its related health impact. The study result showed when this new regulation is fully implemented in the ger districts, the annual consumption of coal and wood would be decreased by about 550,000 tons and 415,000 tons, accompanied by massive reduction of the emission. These changes would lead into noteworthy health benefits such as 15.7 and 17.4 percent of reduction of total and infant mortality rates and 4.3 and 4.7 percent decrease of cardiovascular and respiratory disease morbidity cases, annually.
163

Effects of Biodiesel Fuelling on Diesel Particulate Matter

Ketterer, Justin 06 January 2011 (has links)
Diesel particulate matter (PM) produced from Ultra Low Sulfur Diesel (ULSD), Soy-derived B20 and Animal fat-derived B20 was collected at two engine operating conditions. Gravimetric analysis showed the PM emissions to depend on both fuel and engine operating condition. B20 fuels exhibited higher PM emissions at low load conditions, but lower PM emissions under high load conditions. The differences between the operating conditions were less significant for B20 fuels than for ULSD. Elemental Carbon analysis revealed the B20 PM to contain greater proportions of organic carbon, which may improve diesel particulate filter (DPF) regeneration. Finally, TEM images showed considerable differences between ULSD and B20 soot at low engine loads. The B20 soot displayed a more disordered arrangement of graphene layers. At higher loads, the differences are subtle, but the B20 PM still displayed a more amorphous structure. There was little difference between the Soy and Animal fat-derived B20 soot.
164

Experimental Investigation of the Effects of Fuel Properties on Combustion Performance and Emissions of Biomass Fast Pyrolysis Liquid-ethanol Blends in a Swirl Burner

Moloodi, Sina 14 December 2011 (has links)
Biomass fast pyrolysis liquid, also known as bio-oil, is a promising renewable fuel for heat and power generation; however, implementing crude bio-oil in some current combustion systems can degrade combustion performance and emissions. In this study, optimizing fuel properties to improve combustion is considered. Various bio-oils with different fuel properties are tested in a pilot stabilized spray burner under very close flow conditions. Effects of solids, ash and water content of bio-oil as well as ethanol blending were examined. The results show the amount of solids and ash fractions of the fuel were correlated with combustion efficiency. The CO and unburned hydrocarbon emissions decreased with both water and ethanol content. Increasing the fuel’s volatile content by blending in ethanol has been shown to improve flame stability. Also, the organic fraction of particulate matter emissions was found to be a strong function of the thermogravimetric analysis residue of the fuel.
165

Effects of Biodiesel Fuelling on Diesel Particulate Matter

Ketterer, Justin 06 January 2011 (has links)
Diesel particulate matter (PM) produced from Ultra Low Sulfur Diesel (ULSD), Soy-derived B20 and Animal fat-derived B20 was collected at two engine operating conditions. Gravimetric analysis showed the PM emissions to depend on both fuel and engine operating condition. B20 fuels exhibited higher PM emissions at low load conditions, but lower PM emissions under high load conditions. The differences between the operating conditions were less significant for B20 fuels than for ULSD. Elemental Carbon analysis revealed the B20 PM to contain greater proportions of organic carbon, which may improve diesel particulate filter (DPF) regeneration. Finally, TEM images showed considerable differences between ULSD and B20 soot at low engine loads. The B20 soot displayed a more disordered arrangement of graphene layers. At higher loads, the differences are subtle, but the B20 PM still displayed a more amorphous structure. There was little difference between the Soy and Animal fat-derived B20 soot.
166

Experimental Investigation of the Effects of Fuel Properties on Combustion Performance and Emissions of Biomass Fast Pyrolysis Liquid-ethanol Blends in a Swirl Burner

Moloodi, Sina 14 December 2011 (has links)
Biomass fast pyrolysis liquid, also known as bio-oil, is a promising renewable fuel for heat and power generation; however, implementing crude bio-oil in some current combustion systems can degrade combustion performance and emissions. In this study, optimizing fuel properties to improve combustion is considered. Various bio-oils with different fuel properties are tested in a pilot stabilized spray burner under very close flow conditions. Effects of solids, ash and water content of bio-oil as well as ethanol blending were examined. The results show the amount of solids and ash fractions of the fuel were correlated with combustion efficiency. The CO and unburned hydrocarbon emissions decreased with both water and ethanol content. Increasing the fuel’s volatile content by blending in ethanol has been shown to improve flame stability. Also, the organic fraction of particulate matter emissions was found to be a strong function of the thermogravimetric analysis residue of the fuel.
167

Kietųjų dalelių koncentracijos poveikis Petrašiūnų ir Dainavos mikrorajonų lankančių vaikų susirgimo bronchitu rizikai / Effect of fine particulate matter on bronchitis in preschool children in Petrašiūnai and Dainava

Čiuldienė, Dovilė 20 June 2012 (has links)
Vis daugiau epidemiologinių tyrimų atskleidžia neigiamą oro taršos įtaką žmonių sveikatai. Ypač oro taršos neigiamam poveikiui yra jautrūs maži vaikai. Todėl, siekiant nustatyti ryšį tarp oro taršos kietosiomis dalelėmis ir bronchito rizikos, atlikome oro kokybės ir epidemiologinį „atvejis – kontrolė“ tyrimą. Nustatėme, kad vidutinė sezoninė kietųjų dalelių koncentracija dviejuose mikrorajonuose svyravo nuo 20 µg/m3 iki 41 µg/m3, o vidutinė metinė - svyravo nuo 24 µg/m3 iki 33 µg/m3. Didžiausia vidutinė metinė koncentracija 2010 ir 2011 nustatyta Petrašiūnuose. Atliekant „atvejis – kontrolė” nustatėme, kad Petrašiūnuose iki penkerių metų amžiaus vaikų bronchito paplitimas yra didesnis - 69% visų tirtų vaikų, kai Dainavoje – tik 49 % visų tirtų vaikų. Kontroliuojant ryšį iškraipančius veiksnius, nustatėme, kad riziką susirgti bronchitu dididno suaugusiųjų rūkymas ir vitamino D trūkumas. Tyrimo analizė leido padaryti išvadą, kad vaikams, gyvenantiems ir lankantiems darželius Petrašiūnų mikrorajone, rizika susirgti bronchitu buvo 2,9 karto (PI 95 % 1,789 – 4,716) didesnė, nei vaikams, kurie gyveno ir lankė darželius Dainavos mikrorajone. Taip pat nustatyta, kad berniukams rizika susirgti bronchitu yra didesnė, nei mergaitėms. / There are plenty of epidemiological researches reveal that, exposure to air pollution is associated with numerous effects on human health. The association of PM 10 with the prevalence of bronchitis among till 5 years old children was examined in a cross-sectional study. We found out that, average seasonal pm 10 concentration varied from 20 µg/m3 till 41 µg/m3. And average pm 10 concentration and counted in every year varied from 24 µg/m3 till 33 µg/m3. The highest average yearly pm 10 concentration was determined in Petrašiūnai 2010 and 2011 years. Also we found out that, the prevalence of bronchitis between 5 years old children was higher in Petrašiūnai (69%). The prevalence of bronchitis in Dainava was 49 %. Controlling the factors perverting connection we found out that, smoking and indoor smoking also deficiency of D vitamin have the tendency to increase the risk of bronchitis. In conclusion, we found that, children who lived and used to go to kindergartens in Petrašiūnai the risk of the bronchitis was 2,9 (PI 95 % 1,789 – 4,716).
168

Kietųjų dalelių pernašos tyrimai atmosferoje SILAM modeliu / Particulate matter transport in the atmosphere research using silam model

Mažeikis, Adomas 09 July 2011 (has links)
Šiame darbe atliekamas kietųjų dalelių dispersijos modeliavimas SILAM modeliu pernašos atmosferoje tyrimo tikslais, pateikiami modelio rezultatai, išvados. Lietuvoje yra sąlygos efektyviam modelio darbui bei poreikis modeliuoti ir prognozuoti atmosferos teršalų sklidimą, todėl šio darbo rezultatas ir darbo metu sukurta modelio nustatymo metodika galėtų būti plačiai naudojami praktikoje. Kol kas nėra gausios informacijos apie atmosferos taršos modeliavimą Lietuvos teritorijoje. Atliekami tik matavimai ir regioniniu bei valstybės mastu naudojami kaimyninių valstybių modeliavimo duomenys, o atskiros savivaldybės teršalų sklaidą atmosferoje modeliuoja mikro masto modeliais. Pagrindinis darbo tikslas: ištirti pagrindines kietųjų dalelių pernašos Lietuvos teritorijoje savybes naudojant SILAM modelį, parengtą kietųjų dalelių dispersijos modeliavimui ir prognozavimui Lietuvos teritorijoje bei kuo naujesnius ir kuo gausesnius duomenis iš Lietuvos institucijų (pavyzdžiui Lietuvos hidrometeorologijos tarnybos, Aplinkos ministerijos ir t.t.). Gauti rezultatai, išvados: 1. Pagal atliktų modeliavimų rezultatus matyti, kad pagrindinė kietųjų dalelių taršos dalis laikosi priežeminiuose troposferos sluoksniuose ir pernešama netoli (šis braižas verčia manyti, kad tai stambiosios frakcijos). Tuo tarpu į aukštesnius sluoksnius patenka keletą ir net keletą dešimčių kartų mažesnė kietųjų dalelių dalis, bet jos pernešamos toliau. 2. Pagal gautus duomenis galima teigti, kad modeliuojamuoju... [toliau žr. visą tekstą] / The main purpose of this diploma thesis “Particulate matter transport in the atmosphere research using SILAM model” (written by Adomas Mažeikis) is to use SILAM model to research the transport of local Particulate matter pollutants and those from neighboring countries too. Emission data was prepared by interpolating EMEP and Statistical Department provided data sets. Meteorological data was taken from Lithuanian HydroMeteorological Service HIRLAM installation. The setup of model was prepared and test runs were made (one of them is simulating fire in oil refinery "Mažeikių nafta"). The results of this thesis are large arrays of past (2007 October - 2008 April) PM10 dispersion data. Grads package was used to perform the analysis of data and these are the conclusions made after the analysis was finished: 1. SILAM model is accurate enough for researching country wide PM10 transport analysis. 2. Each and every model run needs individual setup for best performance. 3. SILAM is not user friendly application and there is a lack of documentation (User guide, Operational instructions and model technical descriptions are available but it does not describe the setup of model in details). 4. Users of SILAM should check model run logs. There is plenty of useful data in there though the format is not very usable. 5. Performed analysis of model run results shows that the biggest part of PM10 aerosol is in the lower levels of the troposphere and that part is transported up to 100km (this can... [to full text]
169

The Role of Particulate Matter in the Development of Hypoxia on the Texas-Louisiana Shelf

Cochran, Emma Mary 16 December 2013 (has links)
In the northern Gulf of Mexico, hypoxia occurs annually during the summer on the Texas-Louisiana shelf. This study examines the distribution of particulate and dissolved components relative to hydrography, to better understand the processes controlling the development of hypoxia. Particulate matter on the Texas-Louisiana Shelf has three major sources – river plumes, primary production, and resuspended sediments. The sources and processes controlling distribution and transport of particles are investigated using optical proxies (backscattering, chlorophyll fluorescence, Colored Dissolved Organic Matter fluorescence (CDOM)), temperature, salinity, dissolved oxygen (DO), and in-situ sampling during June and August 2011 cruises of the Mechanisms Controlling Hypoxia program (hypoxia.tamu.edu). Discrete samples of particulate matter (PM) and particulate organic carbon (POC) concentration were obtained for analysis and calibration of optical instruments interfaced with a profiling CTD, a towed undulating CTD (Acrobat), and the ship’s flow-through system along the shelf from south of Galveston, Texas, to east of the Mississippi delta. The results of this study support a previously hypothesized concept of three primary areas of organic and inorganic particle composition and processes that dominate those areas – river-dominated water, highly productive surface waters, and clear, nutrient-poor low-productivity surface waters. The distribution and bulk composition of particulate matter in the northern Gulf of Mexico, plus the distribution of chlorophyll fluorescence and CDOM suggest that subpycnocline primary production plays a role in determining oxygen concentration in subpycnocline waters away from the river-dominated water.
170

Urban ecosystems and human health in South Africa : examining the relationships between housing, energy, indoor air quality and respiratory health

Savage, Leah Krystyn 03 October 2007 (has links)
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

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