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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.
191

Ice nucleation on uncoated and coated atmospheric mineral dust particles

Eastwood, Michael Logan 11 1900 (has links)
An optical microscope coupled to a flow cell was used to investigate ice nucleation on five atmospherically relevant mineral dusts at temperatures ranging from 233 to 247 K. Kaolinite and muscovite particles were found to be efficient ice nuclei in the deposition mode, requiring relative humidities with respect to ice (RHi) below 112% in order to initiate ice crystal formation. Quartz and calcite particles, by contrast, were poor ice nuclei, requiring relative humidities close to water saturation before ice crystals would form. Montmorillonite particles were efficient ice nuclei at temperatures below 241 K, but poor ice nuclei at higher temperatures. In several cases, there was a lack of quantitative agreement between these data and previously published work. This can be explained by several factors including mineral source, particle size, observation time and surface area available for nucleation. Heterogeneous nucleation rates (Jhet) were calculated from the onset data. Jhet values ranged from 60 to 1100 cm-²s-¹ for the five minerals studied. These values were then used to calculate contact angles (θ) for each mineral according to classical nucleation theory. The contact angles measured for kaolinite and muscovite ranged from 6 to 12º; for quartz and calcite the contact angles were much higher, ranging from 25 to 27º. The contact angles measured for montmorillonite were less than 15º at temperatures below 241 K, and above 20º at higher temperatures. The reported Jhet and θ values may allow for a more direct comparison between laboratory studies and can be used when modeling ice cloud formation in the atmosphere. The roles of H₂SO₄ and (NH4)₂SO₄ coatings on the ice nucleating properties of kaolinite were also investigated. Onset data was collected for H₂SO₄ coated and (NH4)₂SO₄ coated kaolinite particles at temperatures ranging from 233 to 247 K. In contrast to uncoated kaolinite particles, which were effective ice nuclei, H₂SO₄ coated particles were found to be poor ice nuclei, requiring relative humidities close to water saturation before nucleating ice at all temperatures studied. (NH4)₂SO₄ coated particles were poor ice nuclei at 245 K, but effective ice nuclei at 236 K.
192

Optical studies of the upper atmosphere

Bartusek, Karel January 1970 (has links)
iv, 146 leaves : ill., appendices / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Physics, 1971
193

Electronic design aspects and instrumentation techniques of cloud condensation nuclei (CCN) spectrometer

Anegondi, Phanindhra Raju. January 2007 (has links)
Thesis (M.S.)--University of Nevada, Reno, 2007. / "December 2007." Includes bibliographical references (leaves a-b). Online version available on the World Wide Web.
194

Adsorption of water vapor by selected containment aerosols chlorides and cement dust /

Li, Zhiping, January 2006 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on May 6, 2009) Vita. Includes bibliographical references.
195

Characterisation of particulate matter emissions from motor vehicles /

Welburn, Colin T. January 1900 (has links)
Thesis (M. Eng.)--Carleton University, 2001. / Includes bibliographical references (p. 211-219). Also available in electronic format on the Internet.
196

Preliminary modeling of in-duct desulfurization using condensation aerosols

Adikesavalu, Ravichandran. January 1997 (has links)
Thesis (M.S.)--Ohio University, August, 1997. / Title from PDF t.p.
197

Electrodynamic trapping, manipulation, and Raman characterization of single particles and fine particulate clouds /

Aardahl, Christopher L., January 1997 (has links)
Thesis (Ph. D.)--University of Washington, 1997. / Vita. Includes bibliographical references (leaves [116]-124).
198

Preparation of mixed-metal catalysts from non-aqueous solutions via an aerosol process

Zuba, Leonard P. January 1998 (has links)
Thesis (M.S.)--West Virginia University, 1998. / Title from document title page. Document formatted into pages; contains xii, 136 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 131-132).
199

Integrated theoretical and experimental studies of organic atmospheric aerosols /

Jacobson, Michael, January 1997 (has links)
Thesis (Ph. D.)--University of Washington, 1997. / Vita. Includes bibliographical references (leaves [135]-144).
200

Ambient submicron particles in North America their sources, fate, and impact /

Peltier, Richard Edward. January 2007 (has links)
Thesis (Ph.D)--Earth and Atmospheric Sciences, Georgia Institute of Technology, 2008. / Committee Chair: Weber, Rodney J.; Committee Member: Bergin, Michael H.; Committee Member: Huey, L Gregory; Committee Member: Ingall, Ellery D.; Committee Member: Nenes, Athanasios.

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