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Trace elements in coal from Collinsville, Bowen Basin, Australia : in-ground mode of occurrence and behaviour during utilisation /Boyd, Robert John. January 2004 (has links)
Thesis (Ph.D.) - James Cook University, 2004. / Typescript (photocopy) Bibliography: leaves 355-380.
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Trace metal cycling in the central equatorial Pacific : results from the U.S. JGOFS EqPac survey cruises /Chapin, Thomas P., January 1997 (has links)
Thesis (Ph. D.)--University of Washington, 1997. / Vita. Includes bibliographical references (p. [200]-229).
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Trace metal cycling in the central equatorial Pacific results from the U.S. JGOFS EqPac survey cruises /Chapin, Thomas P., January 1997 (has links)
Thesis (Ph. D.)--University of Washington, 1997. / Includes bibliographical references (leaves [200]-229).
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1. Trace metal distributions and stable lead isotopic composition in surface waters along the United States-Mexican boundary in the northeast Pacific ; 2. Trace metal distributions in surface waters along the United States-Mexican boundary multivariate statistical analysis /Sañudo Wilhelmy, Sergio Adolfo. January 1989 (has links)
Thesis (M.S.)--University of California, Santa Cruz, 1989. / Typescript. Includes bibliographical references.
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Comparison of four trace element extractants by isotope dilution analysisVale, 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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Evaluating the efficacy of dietary organic and inorganic trace minerals in reproducing female pigs on reproductive performance and body mineral compositionPeters, James C., January 2006 (has links)
Thesis (Ph. D.)--Ohio State University, 2006. / Title from first page of PDF file. Includes bibliographical references (p. 137-158)
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Trace metal accumulation and toxicity in marine phytoplankton /Miao, Aijun. January 2006 (has links)
Thesis (Ph.D.)--Hong Kong University of Science and Technology, 2006. / Includes bibliographical references (leaves 170-195). Also available in electronic version.
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Bioavailability of Cd, Zn and Se in two marine fish /Zhang, Li. January 2007 (has links)
Thesis (Ph.D.)--Hong Kong University of Science and Technology, 2007. / Includes bibliographical references. Also available in electronic version.
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U-Th-Pb fractionation in selected carbonate and silicate systemsHuang, Yi-Ming January 1995 (has links)
V-Th-Pb fractionation trends, and the associated variations in Pb-isotopes, provide important constraints on the nature, and age, of a wide range of geological processes. This thesis presents three detailed case studies from a carbonatite intrusive complex, lower crustal granulite xenoliths, and young volcanic rocks which represent a range of processes that fractionate V, Th and Pb. New major, trace element and Sr, Nd and Pb isotope results are presented for carbonatites and pyroxenites from the 130 Ma old Jacupiranga complex in southern Brazil. The data preclude simple models in which the Sr-Nd and Sr-Pb isotope arrays are the result of crustal contamination processes, or liquid immiscibility between the carbonatites and magmas similar to those from which the pyroxenites crystallised. The initial Sr, Nd and Pb isotope ratios in the Jacupiranga complex are similar to those in the Parana high-Ti basalts and to the oceanic basalts of the Walvis Ridge and Tristan da Cunha, and were apparently inherited from the mantle source regions associated with incipient magmatism of the Tristan da Cunha hotspot and the opening of the South Atlantic. Most carbonatites have high V/Pb and low Rb/Sr ratios and infiltration and/ or metasomatism by such melts is one process that may be responsible for the negative correlation of U/Pb and Rb/Sr inferred for the source of certain oceanic basalts such as Tristan da Cunha. Correlations between trace and major elements in mostly mafic granulite xenoliths from southern Africa probably result from magmatic processes such as fractional crystallisation and crystal accumulation. From Pb and Nd isotope systematics it can be inferred that the northern Lesotho xenoliths are Proterozoic in age, whereas Cape province xenoliths appear to have been fonned in the Archaean and to have had their Nd isotopes reset in the Proterozoic. Most Pb isotope ratios from the granulites xenoliths are unradiogenic relative to the Geochron, which indicates relatively low V /Pb ratios in the later parts of their histories. The correlation between Pb isotope ratios and K<sub>2</sub>O/A1<sub>2</sub>O<sub>3</sub> in the granulites from Markt is considered to reflect magmatic control of the V /Pb fractionation. The Archaean, and some of the younger mantle derived rocks on the Kaapvaal craton, plot on similar Pb isotope trends. It is argued that segments of the crust and uppennost mantle beneath southern Africa stabilised together in the Archaean, and that both were remobilised in subsequent magmatic and orogenic events. Volcanic rocks in the Northland-Auckland peninsula, New Zealand, range from silica-undersaturated basanites to tholeiites and andesites. Although all the volcanic fields are in intraplate settings, two types of mantle source enrichment can be recognised. One is subduction-related and characterised by high Sr and low Nd isotope ratios and negative Nb anomalies. The other type has geochemical features characteristic of intraplate enriched mantle sources with Sr and Nd isotope ratios and Nb/Ba, Ba/La, similar to HIMV OIB, which has been attributed to the deep recycling of oceanic crust. The differences in Pb isotopes between the two mantle sources, i.e. higher /lB/4 and 7/4, but lower <sup>206</sup>Pb/<sup>204</sup>Pb in the subduction-related material than in the inferred HIMU source, indicate that V/Pb in shallow recycled crustal material tend to be lower than in the deeper recycled material. These case studies confirm that (i) metasomatism by small degree melts can have significant effects on mantle trace element characteristics, (ii) the lower crust is a relatively low 11 environment and crystal accumulation may be an important mechanism in the fractionation of Th and U from Pb, cUld (iii) incorporation of recycled crustal material at different levels can result in different V-Th-Pb fractionation and so, with time, different Pb isotope ratios.
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The spectrographic determination of trace elements in citrus leaves / Spectographic determination of trace elements in citrus leavesBrandt, Peter Jürgen January 1962 (has links)
From Introduction: With the rapidly growing knowledge on trace elements and their influence on plant nutrition the need for accurate and rapid methods for their determination arose. The essential plant nutrients are usually divided into two groups. The major or macronutrient elements, necessary in comparatively large amounts, and the trace or micro-nutrient elements. In the case of plants, the first group includes Sulphur, Phosphorus, Potassium, Magnesium, Calcium and Nitrogen. The essential trace elements are Iron, manganese, Boron, Copper, Zinc, Molybdenum and Chlorine. Cobalt is essential for animal nutrition as a constituent of Vitamin B₁₂, but its essentiality for plants has not yet been proved. The latter group consists of metals which are catalysts in enzyme reactions and whose presence in the plant in minute amount determines whether the plant will be able to complete the vegetative or reproductive stage of its life cycle. Molybdenum may be quoted as an example of an essential trace element. It is generally recognised to be the catalyst responsible for the fixation of Nitrogen.
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