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Showing 1 to 20 of 31 for “"Polysulfides"”.
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Diallyl polysulfides from garlic: mode of action and applications in agriculture.
… class of compounds from garlic are diallyl polysulfides (DAS), containing one to six sulfur atoms in a linear chain. The bioactivity of DAS has been shown to increase with increasing sulfur chain length up to DAS4 and in this study the even higher bioactivity of DAS5 and DAS6 was …
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The Synthesis and Reactions of Sodium and Ammonium Polysulfides in Nonaqueous Media
Made available in DSpace on 2014-12-05T19:37:40Z (GMT). No. of bitstreams: 1 6101608.pdf: 1773257 bytes, checksum: 3d6ba3f1a7e7f63774fb4917ad74cde0 (MD5) Previous issue date: 1961
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Zinc polysulfides as precursors to zinc sulfide and as group transfer reagents
In the first part of the thesis, reactions of zinc powder with solutions of elemental sulfur in various donor solvents are described. Complexes of the type $\rm ZnS\sb6$(N-donor)$\sb2$ are obtained for the ligands tetramethylethylenediamine (TMEDA), N-methylimidazole (MeIm), and …
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Effect of polysulfides on cinnabar solubility, partitioning, and methylation by Desulfovibrio desufuricans
Sulfate reducing bacteria are believed to be the most important methylators of mercury in aquatic systems. Methylation may be controlled by the availability of mercury to these bacteria and therefore may depend on mercury speciation in sulfidic water ...
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The synthesis and characterization of sodium polysulfides for Na-S battery application
… energy storage. The characterization of sodium polysulfides in the Na-S battery systems can offer insightful information to understand the electrochemical reaction mechanism of the Na-S batteries and overcome the "inert" nature of short-chain polysulfides (Na2Sn, 1<n<4) during charge and …
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Importance of Sulfide, Polysulfides, and Elemental Sulfur for Abiotic and Biotic Redox Processes in Sulfur-Metal(loid)Systems
… thiosulfate, elemental sulfur, and polysulfides. Polysulfides are highly reducing and nucleophilic sulfur chains of the general structure Sn2-(n ≥ 2). Due to their high reactivity and instability, inorganic polysulfide analysis is challenging. Currently, the most reliable analytical …
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Development of New Cathodic Interlayers with Nano-Architectures for Lithium-Sulfur Batteries
Issues with the dissolution and diffusion of polysulfides in liquid organic electrolytes hinder the advance of lithium–sulfur (Li-S) batteries for next generation energy storage. To trap and re-utilize the polysulfides, brush-like, zinc oxide (ZnO) nanowires based interlayers were prepared ex-situ …
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Electrocatalysis In Li-S Batteries
… host structures for sulfur and its intermediate polysulfides, the week adsorption of polysulfides on carbon surface and its poor reaction kinetics limits them from practical application. Here, we preset a novel ‘electcatalysis’ approach to stabilize polysulfide shuttle process and also enhance …
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Optical diagnostics of lithium-sulfur and lithium-ion battery electrolytes using attenuated total reflection infrared spectroscopy
… to determine the order and concentration of polysulfides in Li-S battery electrolytes was developed from theoretical models and experimental measurements. The polysulfide diagnostic was used to study the evolution of polysulfides during normal battery operation. The trends observed in the …
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Studies on binary carbon sulfides and their metal complexes
… equivalent of S$\sb2$Cl$\sb2$ gave two carbon polysulfides C$\sb3$S$\sb8$ (1) and C$\sb6$S$\sb{12}$ (2). The eclipsed conformation of C$\sb6$S$\sb{12}$ (2) is noteworthy.
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Beyond Lithium-Ion Technology: Lithium-Sulfur and Potassium-Ion for Better and Cheaper Batteries
… a large TiO2 content that can chemically trap polysulfides and a high porosity CNF scaffold for physically hosting the polysulfides. The combined results in the interlayer increase initial discharge capacity and prolong the cycle life as compared to the cell without this interlayer. In the next …
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Interaction between ferric hydroxides and dissolved sulfide in anoxic aquifers: Pathway and kinetics of iron and sulfur products formation
… that not only elemental sulfur but also polysulfides were the main oxidized sulfur products.. The polysulfides, with predominance of disulfide, accumulated mainly at the mineral surface and could be extracted by methanol with an appropriate pre-treatment with zinc acetate. Therefore, the …
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Electrochemical speciation and quantitative chromatography for modelling of indium bioleaching solutions
… techniques were adapted to quantify polysulfides (Sx2–) and metal ions in leaching and extraction solutions. This cumulative information was used in geochemical modelling. Predominance, Pourbaix, and speciation diagrams were produced to describe and explain the behaviour of multiple …
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The design of a thiokol plant
… reaction between organic dihalides and inorganic polysulfides. They find wide application where resistance to petroleum oils, organic solvents, and low permeability. The purpose of this investigation was to design a Thiokol with a production of 2000 tons per year. Research was conducted to …
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Structural Modification of Interfaces for Sustainable High-Performance Batteries
… with porous silicon anodes and the influence of polysulfides in anode-free systems. The studies further show how stability and lifetime can be improved and transferred to post-lithium systems. As battery demands, especially in mobility, continue to increase, the charging rate capability of LSBs …
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Elucidation of the Various Mechanisms of Antioxidant Activity of Organosulfur Compounds
Polysulfides, produced from olefin sulfurization, are common additives to various petroleum-derived products such as engine oils, hydraulic fluids, rubbers and polymeric materials in an effort to protect these materials from oxidative degradation. The mechanisms by which organosulfur compounds act …
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Biophysical and Functional Characterization of the Persulfide Sensor CstR from Staphylococcus aureus
… sulfide (H2S) and low molecular weight per- and polysulfides and become deleterious at increasing concentrations. For example, H2S functions as a gaseous signaling molecule but at elevated levels can poison cytochrome c oxidase of the electron transport chain. The human pathogen Staphylococcus …
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Sulfur-Based Yolk-Shell Nanoparticles for Lithium Sulfur Batteries
… also serves as an absorption layer to capture polysulfides. The porous gold layer was used to increase conductivity of the material. This unique yolk-shell nanostructure has the potential to enhance the performance of lithium sulfur batteries. This study has provided a template for the design …
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The collectorless flotation of sphalerite
… is responsible for collectorless flotation; ii) polysulfides or metal-deficient sulfides formed as a result of mineral oxidation are responsible for collectorless flotation; and iii) removal of HS- ions, which may render the surface hydrophilic, under oxidizing conditions. The third mechanism is …
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