A role of sulfate ions in the flotation of iron (III) hydroxide.

Aragonite formation and stabilisation in seawater is still an area of active investigation since the thermodynamically stable product at room temperature is calcite. In this manuscript, purely inorganic systems that were found to stabilise aragonite were analysed by various techniques. Dynamic Light Scattering was used to characterise the nucleation behaviour of the system and it was found that the presence of magnesium ions during crystal formation inhibits nucleation overall, not just calcite nucleation. In addition, it was found that sulfate is not necessary to stabilise aragonite. Microanalysis by energy dispersive X-ray spectroscopy (EDS) and electron backscatter diffraction (EBSD) revealed that the aragonite that was formed had a disordered core with, sodium, magnesium and sulfate ions incorporated into the structure. To the best of the authors’ knowledge this is the first time an ACC core in aragonite has been visualised in a completely abiotic, synthetic system (in the absence of organic molecules). Inclusion of these impurities into the structure may explain the stability of aragonite in natural seawaters.

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The role of sulfate ions on distinctive defect emissions in ZnO:Ce3+ nanophosphors - A study on the application in color display systems

Journal of Luminescence ◽

10.1016/j.jlumin.2021.118462 ◽

2021 ◽

Vol 240 ◽

pp. 118462

Author(s):

M.L.A. Letswalo ◽

L. Reddy ◽

A. Balakrishna ◽

H.C. Swart ◽

O.M. Ntwaeaborwa

Keyword(s):

Sulfate Ions ◽

Color Display ◽

Display Systems

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Biogenic factors of geochemical uranium anomalies formation in subsurface waters near to Novosibirsk chemical concentrates plant slurry storage

Геохимия ◽

10.31857/s0016-7525646644-650 ◽

2019 ◽

Vol 64 (6) ◽

pp. 644-650

Author(s):

A. V. Safonov ◽

A. E. Boguslavskii ◽

K. A. Boldyrev ◽

L. V. Zayceva

Keyword(s):

Iron Reduction ◽

Sulfate Ions ◽

Microbial Sulfate Reduction ◽

Microbiological Process ◽

Subsurface Waters ◽

Uranium Migration ◽

Oxygen Migration ◽

Polluted Waters ◽

Aerobic And Anaerobic

This article presents data on the possible impact of aerobic and anaerobic microbiological processes in the upper aquifers to uranium migration t sulfate and nitrate polluted waters near to Novosibirsk chemical concentrate plant. Uranium immobilization is possible in local areas, with high content of organic substances and the most important microbiological process is the redox potential reduction due to aerobic respiration. After that in anaerobicс conditions redox-dependent uranium reduction can be expected. Moreover, in the presence of sulfate ions, further anaerobic processes of microbial sulfate reduction and iron reduction lead to the formation of iron sulphide, which plays the significant role of an antioxidant buffer in the case of oxygen migration.

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Inhibition Effect of Fluoride Ion on Corrosion of 304 Stainless Steel in Occluded Cell Corrosion Stage in the Presence of Chloride Ion

Metals ◽

10.3390/met11020350 ◽

2021 ◽

Vol 11 (2) ◽

pp. 350

Author(s):

Zhengwei Luo ◽

Jie Zuo ◽

Hui Jiang ◽

Wenhua Geng ◽

Yongzhang Zhou ◽

...

Keyword(s):

Stainless Steel ◽

Chloride Ion ◽

304 Stainless Steel ◽

Composite Electrodes ◽

Sulfate Ions ◽

Inhibition Effect ◽

Layer Composite ◽

Concentration Of Ions ◽

Corrosion Cell

The role of F− in the corrosion of stainless steel at the stage of occluded cell corrosion in a mixture of chloride, fluoride, and sulfate ions was investigated. A simulated occluded corrosion cell was designed using an elaborate simulated rust layer. Composite electrodes were used to monitor the variation of the concentration of ions, pH, and dissolved oxygen of the occluded solution. The results show that the influence of F− on the corrosion of 304 stainless steel, in the occluded cell corrosion stage, is concentration dependent. When the F−/Cl− ratio is higher than 2, the corrosion can be significantly suppressed. Analyses showed that the corrosion inhibition effect could be attributed to the migration of F− to the occluded cell, which can reduce the migration of Cl−, dampen the decrease in pH, and react with metal ions to form semi-soluble products. Meanwhile, the influence of F− on the corrosion process was also verified using drilled stainless steel specimens, demonstrating the practicality and validity of the simulated occluded cell corrosion model.

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Structural and Biochemical Studies of Bacillus subtilis MobB

Crystals ◽

10.3390/cryst11101262 ◽

2021 ◽

Vol 11 (10) ◽

pp. 1262

Author(s):

Dajeong Kim ◽

Sarah Choi ◽

Hyunjin Kim ◽

Jungwoo Choe

Keyword(s):

Bacillus Subtilis ◽

Binding Assay ◽

Phosphate Binding ◽

Redox Enzymes ◽

Sulfate Ions ◽

Gtp Binding ◽

Biochemical Studies ◽

Activity Enhancement ◽

Β Sheet

The biosynthesis of molybdenum cofactor for redox enzymes is carried out by multiple enzymes in bacteria including MobA and MobB. MobA is known to catalyze the attachment of GMP to molybdopterin to form molybdopterin guanine dinucleotide. MobB is a GTP binding protein that enhances the activity of MobA by forming the MobA:MobB complex. However, the mechanism of activity enhancement by MobB is not well understood. The structure of Bacillus subtilis MobB was determined to 2.4 Å resolution and it showed an elongated homodimer with an extended β-sheet. Bound sulfate ions were observed in the Walker A motifs, indicating a possible phosphate-binding site for GTP molecules. The binding assay showed that the affinity between B. subtilis MobA and MobB increased in the presence of GTP, suggesting a possible role of MobB as an enhancer of MobA activity.

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Corrosion of Post-Tensioned Tendons with Deficient Grout, Part 1: Electrochemical Behavior of Steel in Alkaline Sulfate Solutions

CORROSION ◽

10.5006/2541 ◽

2017 ◽

Vol 74 (3) ◽

pp. 362-371 ◽

Cited By ~ 5

Author(s):

K.K. Krishna Vigneshwaran ◽

S. Permeh ◽

M. Echeverría ◽

K. Lau ◽

I. Lasa

Keyword(s):

Passive Film ◽

Alkaline Solutions ◽

Corrosion Mechanism ◽

Solution Ph ◽

Steady State Condition ◽

Sulfate Ions ◽

Sulfate Solutions ◽

Corrosion Of Steel ◽

Post Tensioned

Severe corrosion recently documented in Florida post-tensioned bridges were related to grout segregation that created deficient grout with characteristics of having low chloride content, high sulfate concentration, high pore water pH, and high moisture content. The role of elevated sulfate concentrations in the development of steel corrosion in deficient grout has not been elucidated. As first approach to determine the corrosion mechanism of steel strand in deficient grout, the objective of the research, described here, was to evaluate the role of sulfate ions on the corrosion of steel in alkaline solutions. Steel coupons were exposed to two different alkaline solutions (SPS) simulating pore solutions with pH 12.6 (SPS1) or 13.3 (SPS2) with varying sodium sulfate levels (early fixed content and later increments). Electrochemical experiments included the steady-state condition and potentiodynamic polarization tests. Solution pH was found as an important parameter in the corrosion development of steel in sulfate SPS solutions. In the highly SPS2 solution (pH 13), sulfate ions did not impair passive film growth or stability. In the moderate SPS1 solution (pH 12.6), early fixed sulfate presence could be aggressive by impairing passive film development; however, even high levels of later increments of sulfates cannot depassivate steel. The instability of the passive film in alkaline sulfate solutions resulted in pitting corrosion of steel.

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Interference by Formaldehydogenic Drugs in the Quantitative Determination of Urinary Hydroxyindoleacetic Acid

Clinical Chemistry ◽

10.1093/clinchem/13.5.397 ◽

1967 ◽

Vol 13 (5) ◽

pp. 397-405 ◽

Cited By ~ 3

Author(s):

Maurice E Shils

Keyword(s):

Sulfate Ions ◽

Color Development ◽

Normal Individuals ◽

Hydroxyindoleacetic Acid ◽

Qualitative Test ◽

Per Se ◽

Development In Vitro

Abstract The administration of methenamine mandelate (Mandelamine) to normal individuals and patients with carcinoid resulted in a marked reduction in apparent urinary hydroxyindoleacetic acid (HIAA) as determined by the quantitative nitroso-naphthol method. Mandelamine, methenamine, and formaldehyde inhibited the normal color development in vitro. The interfering reaction is dependent on an acid pH and is not reversed by raising the pH. It is suggested that formaldehyde is the active substance and the role of mandelamine and methenamine is that of a precursor of this substance in acid solution. Chloride and sulfate ions, per se, caused a definite but limited interference with the color reaction. Under the conditions of this study, mandelamine did not prevent detection of elevated urinary HIAA by the qualitative test for HIAA.

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The role of sulfate ions in tricalcium aluminate hydration: New insights

Cement and Concrete Research ◽

10.1016/j.cemconres.2020.105973 ◽

2020 ◽

Vol 130 ◽

pp. 105973 ◽

Cited By ~ 2

Author(s):

Xin Liu ◽

Pan Feng ◽

Chen Lyu ◽

Shaoxiong Ye

Keyword(s):

Sulfate Ions ◽

Tricalcium Aluminate

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Stabilisation of Aragonite: The Role of Mg2+ and Other Impurity Ions

10.26434/chemrxiv.11364857.v1 ◽

2019 ◽

Author(s):

Matthew Boon ◽

William Rickard ◽

Andrew Rohl ◽

Franca Jones

Keyword(s):

Electron Backscatter Diffraction ◽

Crystal Formation ◽

Sulfate Ions ◽

Inorganic Systems ◽

Sodium Magnesium ◽

Stable Product ◽

The Stability ◽

Backscatter Diffraction ◽

First Time

Aragonite formation and stabilisation in seawater is still an area of active investigation since the thermodynamically stable product at room temperature is calcite. In this manuscript, purely inorganic systems that were found to stabilise aragonite were analysed by various techniques. Dynamic Light Scattering was used to characterise the nucleation behaviour of the system and it was found that the presence of magnesium ions during crystal formation inhibits nucleation overall, not just calcite nucleation. In addition, it was found that sulfate is not necessary to stabilise aragonite. Microanalysis by energy dispersive X-ray spectroscopy (EDS) and electron backscatter diffraction (EBSD) revealed that the aragonite that was formed had a disordered core with, sodium, magnesium and sulfate ions incorporated into the structure. To the best of the authors’ knowledge this is the first time an ACC core in aragonite has been visualised in a completely abiotic, synthetic system (in the absence of organic molecules). Inclusion of these impurities into the structure may explain the stability of aragonite in natural seawaters.

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