No description available.

Measuring air pollution emissions from agricultural activities is usually difficult because of their large area and variability. Traditional air quality sensors, called point samplers, measure conditions in one location, which may not adequately measure a plume. Remote sensors, instruments that measure pollution along a line rather than at a single point, are better able to measure conditions around large areas. This dissertation reports on four agricultural air emissions studies that used both point and remote sensors for comparison. The methods used to calculate the emissions are based on previous work and are further developed in these studies. In particular, an atmospheric dispersion model was developed and tested that can account for a particle behaving different than the surrounding gas due to gravity and inertia and depositing out of the flow. Particulate matter (PM) emissions values are reported for two agricultural tillage conservation management practices (CMPs)and the corresponding traditional tillage methods in order to determine how well the CMP reduces emissions. In addition, gas-phase ammonia (NH3) emissions for a dairy operation and PM emissions from a feedlot operation are reported. These studies can help us better measure emissions from agricultural operations and understand how much air pollution is being emitted.

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第18476号 / 農博第2076号 / 新制||農||1025(附属図書館) / 学位論文||H26||N4860(農学部図書室) / 31354 / 京都大学大学院農学研究科地域環境科学専攻 / (主査)教授 舟川 晋也, 教授 縄田 栄治, 教授 間藤 徹 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第18577号 / 工博第3938号 / 新制||工||1605(附属図書館) / 31477 / 京都大学大学院工学研究科都市環境工学専攻 / (主査)教授 米田 稔, 教授 高野 裕久, 教授 清水 芳久 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第21362号 / 工博第4521号 / 新制||工||1704(附属図書館) / 京都大学大学院工学研究科都市環境工学専攻 / (主査)教授 高野 裕久, 教授 米田 稔, 准教授 上田 佳代 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

No description available.

京都大学 / 新制・論文博士 / 博士(工学) / 乙第13492号 / 論工博第4201号 / 新制||工||1785(附属図書館) / (主査)教授 米田 稔, 教授 高野 裕久, 教授 松井 康人 / 学位規則第4条第2項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

Askackumulering i dieselpartikelfilter är ett välkänt problem som resulterar i ett förhöjt mottryck och påverkad prestanda hos fordonet. Däremot ges sällan uppmärksamhet åt filtrets katalytiska aktivitet och hur det påverkas vid förekomst av avgasföroreningar. Syftet med denna studie är att undersöka effekten av aska på filtrets katalytisk aktivitet och dess förmåga att oxidera föroreningar som är skadliga för miljön och människors hälsa. Dessutom utvärderas askbeläggningsmetoden varpå filtren laboratoriskt åldras med olika typer, samt varierande mängder, av aska för att försöka simulera åldring i fält. Filtrens ytegenskaper karakteriserades genom analys med optisk mikroskopi, SEM-EDS och XRF. Den katalytiska aktivitet undersöktes i en SCAT-rigg, varpå oxidationstester av NOx och C3H8 utfördes. Det färska och fältåldrade jämfördes med de laboratorieåldrade filtren som dopats med 22 g/L respektive 47 g/L CaSO4 samt ett filter dopat med 79 g/L aska. Den katalytiska aktiviteten för laboratorieåldrade filtren liknande det färska filtret. Det fältåldrade filtret hade däremot låg katalytisk aktivitet för oxidation av NO och nästan helt deaktiverat för oxidation av C3H8. I det åldrade filtret och det laboratorieaskabelagda filtren visade EDS att elementen Ca och S hade väl matchade deponeringsregioner på filterkanalytan, vilket indikerade förekomst av CaSO4. Den mikroskopiska analysen indikerade också att båda proverna hade homogen fördelning av aska på filterkanalytan. Trots likheten i de fysiokemiska egenskaperna hos filterkanalytan hos det fältåldrade och laboratorieaskbelagda filtren hade de signfikant olika resultat vid test av katalytisk aktivitet. Deaktiveringen av det åldrade filtret kan ha orsakats av andra typer av åldringsmekanismer. Den valda metoden är inte adekvat för att efterlikna åldring i fält. Ytterligare studier krävs för att utvärdera metoden och effekterna av aska på den katalytiska aktiviteten / Accumulation of ash on the Catalytic Diesel Particulate Filter (CDPF) is a well-known problem that results in elevated back pressure and affected vehicle performance. However, attention is seldom paid to the catalytic performance of the filter, and how it is affected by impurities from the exhaust. The objective of this study is to address the effect of ash on the catalytic performance of CDPF to oxidise pollutants that are harmful to the environment and human health. In addition, evaluating the feasibility to laboratory age CDPFs with different loads and compositions using the dip-coating method to simulate field aged filters. The filter characterisation was analysed by Optical Microscopy, Scanning Electron Microscopy (SEM) with Electron dispersive X-ray Spectroscopy (EDS), and X-ray Fluorescence (XRF). The catalytic performance was investigated based on NOx and C3H8 oxidation tests in a Synthetic Catalyst Activity Test (SCAT) rig. A fresh and field aged filter was compared with laboratory aged filters prepared with coatings of 22 g/L and 47 g/L CaSO4, and 79 g/L ash , respectively. The catalytic activity to oxidise NO and C3H8 was unaffected by the ash deposits in the laboratory aged filters, showing similar activity as the fresh filter. While the field aged filter had low catalytic performance to convert NO and was almost completely deactivated for the oxidation of C3H8. EDS mapping for the field aged filter and the laboratory ash coated sample showed that the elements Ca and S were present and had well-matched regions of deposit, respectively, indicating that CaSO4 was present. The microscopic analysis also indicated that both samples had a homogeneous distribution of ash on the filter channel surface. Despite the similarity in the physicochemical properties of the filter channel surface(field aged filter and the laboratory ash coated sample) the catalytic activity had significantly different results. This study suggests that the deactivationof the field aged filter might be caused by other types of ageing mechanism. The laboratory ageing by dip-coating is seen as a non-applicable method to simulate field aged filters. Further studies are required to evaluate both the method and the effects of ash on the catalytic activity.

No description available.

Tropospheric fine particulate matter (PM) poses serious health risks and has a significant impact on global climate change. The measurement of various aspects of PM is challenging due to its complex chemical nature. This dissertation addresses various aspects of PM, including composition, measurement, and visibility. The U.S. Environmental Protection Agency (EPA) proposed a new secondary standard based on visibility in urban areas using 24-h averaged measurements of either light scatter or PM concentration. However shorter averaging times may better represent human perception of visibility. Data from two studies conducted in Lindon, UT, 2012, and Rubidoux, CA, 2003, were used to compare different techniques to estimate visibility, particularly the effect of relative humidity on visibility estimations. Particle composition was measured in Salt Lake City during January-February of 2009. One-hour averaged concentrations of several gas phase and particle phase inorganic species were measured. The results indicate ammonium nitrate averages 40% of the total PM2.5 mass in the absence of inversions and up to 69% during strong inversions. Also, the formation of ammonium nitrate is nitric acid limited, while the formation of ozone appears to be oxidant and volatile organic carbon (VOC) limited. Reduction of NOx will reduce ammonium nitrate secondary particle formation, however, a decrease in NOx may increase ozone concentration.Due to the complexity of PM it is poorly characterized. A large fraction of PM is composed of organic compounds, but these compounds are not regularly monitored due to limitations in current sampling techniques. The GC-MS Organic Aerosol Monitor (OAM) combines a collection device with thermal desorption, gas chromatography and mass spectrometry to quantitatively measure the carbonaceous components of PM on an hourly averaged basis. A compact GC and simple pre-concentrator were developed for the system to decouple separation from manual injection and enhance separation of environmentally-relevant polar organic compounds, such as levoglucosan. The GC-MS OAM is fully automated and has been successfully deployed in the field. It uses a chemically deactivated filter for collection followed by thermal desorption and GC-MS analysis. Laboratory tests show that detection limits range from 0.2 to 3 ng for many atmospherically relevant compounds. The GC-MS OAM was deployed in the field for semi-continuous measurement of the organic markers, levoglucosan, dehydroabietic acid, and several polycyclic aromatic hydrocarbons (PAHs) during winter (January to March), 2015 and 2016. Results illustrate the significance of this monitoring technique to more fully characterize the organic components of PM and identify sources of pollution.