Global ETD Search
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Showing 1 to 13 of 13 for “"Greigite"”.
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Fundamental magnetic properties of Greigite (Fe3S4)
Over the last twenty years, greigite (Fe3S4), an authigenic magnetic iron sulphide mineral, has been increasingly identified in sulphate-reducing marine and lacustrine sedimentary systems. Its presence can significantly affect palaeomagnetic and environmental magnetic records. Understanding the …
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Ripening Kinetics of Iron Sulfides in the Presence/Absence of a Carbonyl Group
… of mackinawite (Fe₁+ₓS) to pyrite (FeS₂) or greigite (Fe²⁺Fe³⁺ ₂S₄) was examined at temperatures between 23 and 90°C to better understand the kinetics of low temperature iron sulfide crystallization in the presence or absence of aldehydes. Mackinawite starting material was synthesized in a …
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Geobiology of marine magnetotactic bacteria
… membrane-bound crystals of magnetite (Fe3O4) or greigite (Fe3S4), and are abundant in the suboxic to anoxic zones of stratified marine environments worldwide. Their population densities (up to 105 cells ml-1) and high intracellular iron content suggest a potentially significant role in iron …
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Geobiology of marine magnetotactic bacteria
… membrane-bound crystals of magnetite (Fe3O4) or greigite (Fe3S4), and are abundant in the suboxic to anoxic zones of stratified marine environments worldwide. Their population densities (up to 105 cells ml−1) and high intracellular iron content suggest a potentially significant role in iron …
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The Geochemistry of Selenium and Sulfur in a Coastal Salt Marsh
… In contrast, the depth distribution of greigite did not show appreciable changes with season. Pyrite underwent large concentration changes in the upper 15 cm of sediment during spring, but remained relatively constant with respect to concentration and distribution below this zone. Using …
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The redox and iron-sulfide geochemistry of Salt Pond and the thermodynamic constraints on native magnetotactic bacteria
… cocci occupy the top of the chemocline and greigite-producing MB occur at the base of the chemocline and in the sulfidic hypolimnion. This distribution may be attributed to analyte profiles within the pond; depth profiles show a sudden drop of dissolved oxygen (DO) at the chemocline …
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The redox and iron-sulfide geochemistry of Salt Pond and the thermodynamic constraints on native magnetotactic bacteria
… cocci occupy the top of the chemocline and greigite-producing MB occur at the base of the chemocline and in the sulfidic hypolimnion. This distribution may be attributed to analyte profiles within the pond; depth profiles show a sudden drop of dissolved oxygen (DO) at the chemocline …
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Microbially influenced corrosion in sour environments
… corrosion product was found to be a mixture of greigite and marcasite. However, this composition was observed to change irreversibly with the application of a laser that caused the material to either heat and/or dry. The resulting golden-colored corrosion product was found to consist mainly of …
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Neogene paleomagnetism and geodynamics of the Hikurangi margin, East Coast, New Zealand
… predominantly the ferrimagnetic iron sulphide, greigite, which is present as a mixed population of single domain and superparamagnetic grains that are characteristic of arrested authigenic growth. Strong viscous overprints are the result of later, usually recent, oxidation of these sulphides. …
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Synthesis of Cadmium, Lead and Iron Sulfide Thin Films and Nanoparticles
… nanostructures. Furthermore, optically active greigite and pyrrhotite-iron sulfide nanoparticles were prepared by simply varying the temperature of the hot solvent. Pyrrhotite-Fe1-XS sensor device showed interesting performance when tested for humidity and different nitrogenous gases such NO2 …
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A methodology for studying denitrification by recently formed sulfides
… iron monosulfide (FeS), mackinawite (FeS), and greigite (Fe3S4). The objective of this research was to design and begin implementing a methodology for investigating the effects of recently formed sulfides on denitrification. </p><p> In order to begin investigating the denitrification potential …
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The Chemodenitrification of Nitrate by Green Rust and Mackinawite and its Geochemical Implications
… surfaces. These oxidation products included greigite (Fe3S4), elemental sulfur (S0), thiosulfate (S2O32-) and sulfate (SO42-), suggesting that both Fe and S participated in the reduction of NO3-. In this case, the major reduced N species was N2(g), and not NH4+. No N and O stable isotope …
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Forming magnetic chain with the help of biological organisms
… nanoparticle, either magnetite (Fe3O4) or greigite (Fe3S4), embedded in a membrane. The chain is assembled along an actin-like scaffold made of MamK protein, which makes the magnetosomes to arrange in mechanically stable chains. The chains work as a compass needle in order to allow cells to …