Sulfur Oxidation
Mostrando 1-12 de 265 artigos, teses e dissertações.
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1. FAST DETERMINATION OF THE SULFUR SPECIES IN SOLID PHASE SYSTEMS BY A TPO-IR METHOD
Qualitative and quantitative assessment of total sulfur and sulfur species in solid phase is necessarily important for development of effective desulfurization methods, reduction of environmental pollution, and prevention of catalyst poisoned. In this work, TPO-IR (Temperature Programmed Oxidation- Infrared) method was used for rapid determination of sulfur
Quím. Nova. Publicado em: 2021-01
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2. SEPARATION OF SULFUR-CONTAINING COMPOUNDS FROM DIESEL BY OXIDATION FOLLOWED BY SOLVENT EXTRACTION IN A SINGLE DROP COLUMN
Abstract Oxidative desulfurization (ODS) is an attractive complementary or alternative process for the hydrodesulfurization (HDS) process due to advantages such as mild operating conditions. In the ODS process, the sulfur-containing compounds are oxidized first to polar sulfoxide and sulfone products and then these polar compounds are separated using solvent
Braz. J. Chem. Eng.. Publicado em: 09/12/2019
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3. Long-term behavior of mortars produced with sulfide-bearing aggregates
ABSTRACT The variety of sulfides (inorganic compounds formed by combining sulfur with a metal element) presented in earth crust is not small, which makes it difficult to avoid the use of sulfide-bearing aggregates in the concrete, especially in places where another source of material is non-existent or economically impracticable, as is the case of dams. With
Matéria (Rio J.). Publicado em: 25/11/2019
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4. Elemental Concentration and Sulfur Chemical Speciation in the Amazonian Plant Andira surinamensis Using Synchrotron Radiation Techniques (SR-XRF, XANES), RBS and WD-XRF
The inorganic composition of the bark and leaf of a plant from the Amazon rainforest, Andira surinamensis, was determined using two non-destructive, multi-element techniques: X-ray fluorescence (XRF) and Rutherford backscattering spectrometry (RBS). XRF measurements were made using both a conventional X-ray source and synchrotron radiation. It was observed t
J. Braz. Chem. Soc.. Publicado em: 16/09/2019
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5. [PROVISIONAL] Genome-wide analysis of the transcriptional response to drought stress in root and leaf of common bean
Abstract Genes related to the response to drought stress in leaf and root tissue of drought-susceptible (DS) and tolerant (DT) genotypes were characterized by RNA-Seq. In total, 54,750 transcripts, representative of 28,590 genes, were identified; of these, 1,648 were of high-fidelity (merge of 12 libraries) and described for the first time in the Andean germ
Genet. Mol. Biol.. Publicado em: 12/08/2019
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6. CHARACTERIZATION OF SEVERAL GENERATIONS OF NiMo HYDROPROCESSING CATALYSTS EMPLOYED IN THE SAME HYDROTREATER
This work details the chemical characterization of four NiMo/Al2O3 hydroprocessing generation catalysts (1979-1986, 1993-1998, 2003-2008 and 2008-2011) employed to perform hydrodesulfurization (HDS) of diesel fractions in the same hydrotreater of a Brazilian refinery. The basic differences are the quality of the feedstocks and the HDS experimental conditions
Quím. Nova. Publicado em: 27/05/2019
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7. Relationship between Electrochemical Parameters, Cytotoxicity Data against Cancer Cells of 3-Thio-Substituted Nor-Beta-Lapachone Derivatives. Implications for Cancer Therapy
Electrochemical methods are powerful in the characterization and design of redox-modulating agents. We, herein, report the electrochemical investigation, in aprotic medium, of eleven synthetic 3-thio-substituted-nor-beta-lapachones, along with the determination of cytotoxic activity and correspondent selectivity index, against several cancer cell lines and o
J. Braz. Chem. Soc.. Publicado em: 2019-03
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8. The Iron Sulfides Crystal Growth from the Halide Melts
A new approach to a single crystals growth of the iron sulfide phases of definite structure and nonstoichiometry is developed and applied. This approach is based on the method of crystal growing from solution melts. This approach is based on the crystallization or recrystallization of iron sulfides from iron sulfide solutions in iron dihalide melts under fix
Mat. Res.. Publicado em: 21/05/2018
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9. N-Acetyl-cysteine Increases Chemical Stability of Hydroquinone in Pharmaceutical Formulations: a Theoretical and Experimental Approach
In this study, the chemistry stability of hydroquinone (HQ) was evaluated according to its effects in redox properties and compared to kojic acid (KA). The HQ oxidation was more inhibited by N-acetylcysteine (NAC) than ascorbic acid (AA). These results were elucidated using theoretical methods at the DFT/B3LYP level of theory. All electronic parameters were
J. Braz. Chem. Soc.. Publicado em: 2018-03
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10. Anodic Oxidation of Sulfide to Sulfate: Effect of the Current Density on the Process Kinetics
The kinetics of the conversion of sulfide to sulfate by electro-oxidation, using a boron-doped diamond (BDD) electrode was studied. Different applied current densities were tested, from 10 to 60 mA cm-2. The results showed that the electrochemical conversion of sulfide to sulfate occurs in steps, via intermediate production of other sulfur species. The oxida
J. Braz. Chem. Soc.. Publicado em: 2017-04
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11. Pd-Impregnated activated carbon and treatment acid to remove sulfur and nitrogen from diesel
ABSTRACT Removal of sulfur and nitrogen compounds from national commercial diesel through adsorption onto activated carbon was studied. Brazilian commercial activated carbon samples (AC) were modified by acid oxidation and, alternatively, were impregnated with palladium chloride. Modified carbon samples showed a significant increase in the quantity of acid s
Matéria (Rio J.). Publicado em: 2016-06
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12. Sulfites in beer: reviewing regulation, analysis and role
ABSTRACT Beer is an extremely complex mixture of more than 3,000 different compounds in an aqueous environment. Thus, it is perhaps not surprising that the maintenance of beer quality throughout its lifetime has been a considerable challenge for brewers. Whilst it is inevitable that chemical changes will occur in beer with the passage of time, it is the form
Sci. agric. (Piracicaba, Braz.). Publicado em: 2016-04