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Showing 1 to 13 of 13 for “"IRON SULFIDES"”.
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Mechanisms governing the growth, reactivity and stability of iron sulfides
… at the surface. A corrosion system comprising an iron sulfide film (passive layer) formed on iron or steel in contact with an hydrogen sulfide (H₂S)- rich fluid can thus, in principle, be modeled by a series of unit reaction steps that control the rate of degradation under given thermodynamic …
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Ripening Kinetics of Iron Sulfides in the Presence/Absence of a Carbonyl Group
… understand the kinetics of low temperature iron sulfide crystallization in the presence or absence of aldehydes. Mackinawite starting material was synthesized in a glass, thermostatted reaction vessel from aqueous hydrogen sulfide and ferrous ammonium sulfate. Formaldehyde, which acts as an …
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Spatial and temporal variations in the geometry and composition of the Permian Whitehill Formation South Africa
… of this resource unit but also the paleoenvironmental conditions that prevailed in the Karoo Basin during its accumulation. Following the recent global proliferation of unconventional hydrocarbon resources originating in organic-rich shale successions, the WHF is seriously being considered …
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Iron minerals in sedimentary phosphorites of the southeastern United States
… and reflected light microscopy reveals that the iron-bearing minerals associated with these sedimentary phosphorites are related to the geologic setting and degree of weathering of the deposit. Pyrite and marcasite (FeS₂) are the principal iron mineral inclusions in unweathered phosphorites of …
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Microbially influenced corrosion in sour environments
… corrosion when it appears in conjunction with an iron sulfide film. Two model biogels were used: calcium alginate, which has this metal-binding property, and agarose, which does not. In pursuit of this hypothesis, iron sulfide films were grown on mild steel coupons. Two distinct forms of iron …
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Mercury transport through a capped sediment
… literature and our primary experimental results, iron sulfide (FeS) was selected for the following study. By amendment of laboratory synthesized iron sulfide (Syn-FeS) into sediment slurries spiked with Hg(II) under anoxic conditions, the inhibition effects of FeS on the methylation of mercury …
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EFFECTS OF GROUND-WATER FLOW ON SOIL CHEMISTRY, NUTRIENT AVAILABILITY AND PLANT SPECIES DISTRIBUTIONS IN FOUR NEW YORK STATE FENS
… of redox-sensitive ions (e.g., nitrate, iron, sulfate) and alkalinity conformed to GWFs. Equilibrium conditions prevailed with respect to calcium minerals except where ground-water inputs of sulfate induced SO42- -reduction and net dissolution predominated. Iron minerals, including …
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An Investigation of the Geochemistry and Hydrogeology of the Queen Charlotte Fault
… promote the formation of carbonates and iron sulfides that fuel microbial mats and diverse chemosynthetic communities at the seafloor. Analyses of water isotopes and chloride concentrations suggest that certain locations in proximity to the QCF may be influenced by meteoric water, or some …
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The Mineralogy And Chemistry Of Micrometeorites
… being the dominant components, with minor iron-nickel metal and iron sulfides, suggesting a broadly chondritic origin. Fe-Ni rich residue was also identified that would appear to belong to a group of non-chondritic particles previously unrecognised. Possible refractory or Ca/Al rich …
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On the Chemistry of Molecules Containing Silicon, Phosphorus, and Sulfur in the Interstellar Medium
The Interstellar Medium (ISM) is an extreme environment that requires a wide range of experimental techniques to investigate its many shades. This thesis presents a collection of studies in Laboratory Astrochemistry aimed at providing new experimental data for astrochemical modeling and probing the …
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The Chemodenitrification of Nitrate by Green Rust and Mackinawite and its Geochemical Implications
… around abiotic nitrate (NO3-) reduction under environmentally relevant conditions has been undertaken to shed further insight into NO3- chemodenitrification driven by Fe(II)/Fe(III)-bearing minerals. The kinetics of NO3- chemodenitrification in Fe(II)/Fe(III) (oxy)(hydr)oxide heterogeneous systems …
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Kinetic Studies of Sulfide Mineral Oxidation and Xanthate Adsorption
… in sulfide minerals flotation. However, some sulfides are naturally hydrophobic and may float without a collector. Iron sulfides, such as pyrite and pyrrhotite, are few of the most abundant minerals, yet economically insignificant. Their existence with other sulfide minerals leads to an …
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ΜΕΛΕΤΗ ΜΑΓΝΗΤΟΑΝΤΙΣΤΑΣΗΣ ΣΕ ΜΟΝΟΚΡΥΣΤΑΛΛΟΥΣ FE7S8
THIS IS A STUDY OF THE MAGNETORESISTANCE IN ANTIFERROMAGNETIC SEMICONDUCTORS AND SPECIALLY IN PYRRHOTITE FE7S8 CUT FROM NATURAL SINGLE CRYSTALS (WITH ORIENTATIONS B C AND B// FROM 88 TO 607K. BEYOND THE NEEL POINT TN 600K AND FOR MAGNETIC FIELDS B FROM 0 TO 7 KG. A MAGNETORESISTANCE OF THE ORDER OF …