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Showing 1 to 20 of 69 for “"ferric iron"”.
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Spectroscopic Studies of the Reduction of Nitrate and Ferric Iron in Heterogeneous Systems
Made available in DSpace on 2014-12-14T14:37:27Z (GMT). No. of bitstreams: 1 7913374.pdf: 4152412 bytes, checksum: 7056c857f39947c51273650ed323ef07 (MD5) Previous issue date: 1978
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Relative rates of reaction of pyrite and marcasite with ferric iron at low pH
… sources were determined at 25°C and pH = 2.0 in ferric chloride solutions with initial ferric iron concentrations of 10⁻³ molal. The rate of the reaction: FeS₂ + 14Fe³⁺ + 8H₂O = 15Fe²⁺ + 2SO₄²⁻ + 16H⁺ was determined by calculating the rate of reduction of aqueous ferric ion from measured …
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Rates of reaction of covellite and blaubleibender covellite with ferric iron at ph 2.0
… covellite and covellite with 10⁻³ m ferric iron in a pH 2 solution were determined at 25, 35, and 50°C. Ferrous and cupric ion concentrations of the run solutions suggest that parallel reactions oxidized the sulfur to either elemental sulfur or to sulfate. The reaction that produces …
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The effect of trivalent cations on the major lower mantle silicates
… the effect of composition, especially ferric iron and aluminum, on the equations of state and phase stability of perovskite and post-perovskite. The presence of trivalent cations decreases the bulk modulus of perovskite at pressures corresponding to the upper lower mantle. Ferric iron …
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Effects of chronic, sublethal ferric iron exposure on the critical swim speed of rainbow trout (Oncorhynchus mykiss) and critical thermal maximum of cutthroat trout (Oncorhynchus clarkii)
… chronic water quality criterion for total iron. Although the effects of dissolved ferrous iron have been well documented, limited data are available regarding ferric iron specific toxicity in aquatic ecosystems. Juvenile rainbow trout (Oncorhynchus mykiss) critical swim speed (Ucrit) was …
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Characterization of a Catechol-Type Siderophore and the Detection of a Possible Outer Membrane Receptor Protein from <em>Rhizobium leguminosarum</em> strain IARI 312.
… bacteria produce and secrete siderophores under iron-deficient conditions. Siderophores are low molecular weight compounds (600-1500 Daltons), which chelate ferric iron with an extremely high affinity, and the complex is actively transported across the outer and inner membranes of gram-negative …
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Investigating ferric ion production and consumption trends in a simulated e-waste bioleaching environment for maximum metal dissolution efficiency
… considerable focus. Bioleaching using the ferric ion and ferrous ion regeneration cycle is applied to the recovery of metals from metal sulphides in virgin ores and there is growing interest in its application to WEEE. The two sub-processes in the ferric regeneration cycle are ferric ion …
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The kinetics of ferrous iron oxidation by Leptospirillum-like bacteria in absence and in presence of pyrite and pyrite/arsenopyrite mixtures in continous and batch cultures
… i) the mineral sulphide is chemically leached by ferric iron into the metal ion and sulphate and ii) the bacteria regenerate ferric iron. The kinetic parameters of these subprocesses are determined in presence of Leptospirillum-like bacteria as the main ferrous iron oxidizing bacterium. The …
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Interaction between ferric hydroxides and dissolved sulfide in anoxic aquifers: Pathway and kinetics of iron and sulfur products formation
The interaction between ferric iron (Fe(III)) and sulfide (S(-II)) is of great importance in permanent or temporary anoxic environments. It is a major component of the biogeochemical cycling of both iron and sulfur and eventually of carbon. Electron transfer between ferric iron and sulfide leads to …
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The ferric leaching of pyrite
… been found to occur via an indirect mechanism. Ferric iron leaches the pyrite, and is reduced to ferrous iron. Bacteria such as Thiobacillus ferrooxidans oxidise the ferrous iron to ferric iron, thus maintaining a high redox potential. In this thesis, the effect of the redox potential on the …
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Biooxidation and Thiocyanate Leaching of Refractory Gold Ore in One-Step
… and aquatic organisms, and safer for the environment. First, a feasibility study on gold extraction from an oxide ore by thiocyanate leaching was conducted. After a series of experiments designed by the response surface methodology, the optimum condition for maximum gold recovery, 96%, from …
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I. A search for organic compounds as colorimetric quantitative reagents for inorganic ions ; II. A study of the reaction between 2 acetamino 6 amino benzo thiazole and chloroiridic acid
… much as 0.02 mg. per ml. of solution providing ferric iron is absent. If ruthenium is present it must be removed before the test for the iridium anion can be made.
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Iron in oxides, silicates and alloys under extreme pressure-temperature conditions
… sites and the evolution the spin state of ferric iron, as one of crucial parameters determining electrical and radiative conductivity of the Earth's lower mantle. We perform single-crystal x-ray diffraction on magnesium silicate perovskite with the composition Mg0.63Fe0.37Si0.63Al0.37O3 …
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Part I, Preliminary investigation of one-hundred organic compounds as possible colorimetric reagents ; Part II, Solubility of the alkaline earth salts of some higher fatty acids
… 5-Sulfobenzoic Acid. A colorimetric reagent for ferric iron. A further investigation of compound 71A, as a colorimetric reagent for ferric iron, reveals that the sensitivity of this reaction is not great enough for it to be of any practical importance, since we have reagents (2) for this ion that …
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The microbiology of mining leach liquor regeneration
… of Thiobacillus ferrooxidans independently of iron oxidation was developed. This method involved the analysis of protein using the Cobmassie Blue protein-binding assay. It was found to be free from interference by the inorganic ions present in T. ferrooxidans culture medium. The effect of …
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Increasing fermentative butanol production in Clostridium beijerinckii using oxidized extracellular electron shuttling molecules
… over dependence on foreign oil and the environmental impacts of using oil as a major source of fuel have led to increased interest in more sustainable energy options. Bio-butanol, produced during fermentation of plant biomass, is one possible alternative. However, yields for butanol …
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Ferric/ferrous determinations in synthetic biotite
The relationships between ferric iron content and the P-T-fH₂ conditions of formation were examined for two biotite compositions: annite (K₂Fe₅Al₄Si₅O₂₀(OH)₄) and siderophyllite (K₂Fe₆Al₂Si₆O₂₀(OH)₄). The synthesized phases were annealed at fixed hydrogen fugacities using both the solid oxygen …
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Misregulation of Iron Handling Proteins in Excitotoxic Brain Injury
The increased iron has been implicated as a major generator of reactive oxygen species (ROS), which can cause neuronal death in neurodegenerative diseases. The present study was also carried out to elucidate the expression of iron handling proteins such as divalent metal transporter-1 (DMT1) …
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Isolation of a Siderophore Produced by Methicillin-Resistant <em>Staphylococcus aureus</em> Strain H372.
<p>Iron is necessary for many cellular processes such as the electron transport chain and gene regulation. However, most iron on earth is found in insoluble iron-hydroxide complexes. In addition, iron is tightly sequestered in the human body by proteins such as transferrin, making it unavailable …
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Isolation and Identification of the Siderophore "Vicibactin" Produced by <em>Rhizobium leguminosarum</em> ATCC 14479.
<p>Siderophores are small, iron chelating molecules produced by many bacteria to help meet the iron requirements of the cell. Multiple metabolic functions require iron as it serves as a cofactor in many enzymes and cellular processes. However, in the presence of oxygen and at physiologic pH, iron …
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