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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.
71

Implications of shallow groundwater and surface water connections for nitrogen movement in typical Boreal Plain landscapes

Vallarino, Amy 05 September 2014 (has links)
This thesis examines both surface water and shallow groundwater connections in boreal watersheds at two study sites in the Athabasca Oil Sands Region using conventional hydrological techniques as well as stable water isotope techniques. Increased emissions due to oil sands development are expected to contribute significantly to acidifying airborne emissions. Specifically, nitrogen is forecasted to be deposited on the surrounding area within approximately 100 km of operations. The purpose of the research is to provide background information for predicting how individual terrain units such as fens, bogs, and uplands will respond to increased nitrogen loads, and to assess whether or not these units will act as sources or sinks of nitrogen under higher nitrogen deposition. Two study sites situated within 100 km of Fort McMurray, Alberta were instrumented with a total of 30 nested piezometers, 26 water table wells, 4 micro-meteorological stations, and two gauging stations (weirs) at outflow points. Monitoring occurred during the open water season of 2011 and 2012. This study estimates evaporation through a simplified energy balance, documents hydraulic conductivity of shallow aquifers, utilizes stable isotopes of water to assist in mapping seasonal flow patterns, and calculates a vertical water balance for the sites. Bogs and fens were hydrologically connected, as bogs fed fens laterally at shallow depths within the acrotelm during wet years. Upland terrain units were found to have more variable connections. In spring, upland runoff recharged the wetlands at both sites. At JPH groundwater flowed towards the fen, whereas in ML limited connections were observed between the uplands and the fen. Also, no connections were seen to indicate that the wetlands recharged the uplands. A conceptual model is developed that emphasizes the role of connectivity in the boreal landscape. The main implication for nitrogen cycling is that it is difficult to quantify one landscape as a source or sink for additional nitrogen as its role may vary depending on seasonality and temporal scales. Further work is needed to identify if nitrogen loadings will have adverse affects on geochemistry of water at the sites. / Graduate / 0366 / amyvallarino@gmail.com
72

Changes in stable carbon isotopes of methane along a salinity gradient in a hypersaline microbial mat system

Potter, Elyn. January 2007 (has links)
Thesis (M.S.)--University of Missouri-Columbia, 2007. / 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 November 1, 2007) Includes bibliographical references.
73

Dating the paleobeaches of Pampa Mejillones, northern Chile, by cosmogenic chlorine-36

Almasi, Peter Ferenc. January 2001 (has links) (PDF)
Thesis (M.S. - Hydrology and Water Resources)--University of Arizona. / Includes bibliographical references (leaves 119-128).
74

The use of ostracoda in the palaeoenvironmental reconstruction of the Gulf of Carpentaria, Australia, from the last interglacial to present

Reeves, Jessica Marie. January 2004 (has links)
Thesis (Ph.D.)--University of Wollongong, 2004. / Typescript. Includes bibliographical references: p. 366-393.
75

Mudgases geochemistry and factors controlling their variability

Vlad, Daniela. January 2010 (has links)
Thesis (Ph.D.)--University of Alberta, 2010. / Title from PDF file main screen (viewed on Apr. 13, 2010). A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Doctor of Philosophy, Department of Earth and Atmospheric Sciences, University of Alberta. Includes bibliographical references.
76

The production of high specific activity radionuclides for radiotherapy application /

Jia, Wei, January 1996 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 1996. / Typescript. Vita. Includes bibliographical references (leaves 120-126). Also available on the Internet.
77

The production of high specific activity radionuclides for radiotherapy application

Jia, Wei, January 1996 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 1996. / Typescript. Vita. Includes bibliographical references (leaves 120-126). Also available on the Internet.
78

Etude du probleme de l'origine des carbonatites au moyen des isotopes du carbone et de l'oxygene

Pineau, Françoise. January 1900 (has links)
Thesis (doctoral)--Faculté des sciences de Paris, (197-?). / Includes bibliographical references (leaves [43]-[46]).
79

Assessing the effects of LXR agonists in cholesterol handling: stable isotope tracer studies /

Aravindhan, Karpagam. Jucker, Beat M. DiNardo, N. John. January 2005 (has links)
Thesis (Ph. D.)--Drexel University, 2005. / Includes abstract and vita. Includes bibliographical references (leaves 191-199).
80

Comparison of four trace element extractants by isotope dilution analysis

Vale, Rui Ramos do. January 1982 (has links)
Thesis (M.S.)--University of Wisconsin--Madison, 1982. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 112-116).

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