Organic Material
Mostrando 13-24 de 749 artigos, teses e dissertações.
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13. VOLATILE COMPOUNDS IN CACHAÇAS OBTAINED FROM THREE SUGARCANE VARIETIES CULTIVATED UNDER THE MANAGEMENTS: ORGANIC, CONVENTIONAL AND WITHOUT FERTILIZATION
The volatile compounds present in cachaça can derive from the raw material used in the production of the beverage, from the fermentative process, from distillation or aging. The aim of the research was to evaluate the volatile compounds, in the cachaças from stills produced with different sugarcane varieties, under the organic and conventional managements.
Quím. Nova. Publicado em: 2020-09
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14. New Magnetic Fe Oxide-Carbon Based Acid Catalyst Prepared from Bio-Oil for Esterification Reactions
In this work, bio-oil (an organic matrix rich in oxygen functionalities) was used to efficiently dissolve and disperse Fe3+ which upon thermal treatment produced a carbon containing dispersed and encapsulated Fe oxide magnetic nanoparticles. These materials were prepared by dissolution of 8, 16 and 24 wt.% Fe3+ salt in bio-oil followed by treatment at 400, 4
J. Braz. Chem. Soc.. Publicado em: 2020-08
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15. PROCESSING OF A METAL CONCENTRATE FROM GROUND WASTE PRINTED CIRCUIT BOARDS IN ACIDIC MEDIA USING HYDROGEN PEROXIDE AS OXIDANT
The recovery of precious and base metals of a metal concentrate from ground waste printed circuit boards (PCBs) is described in detail. Samples were treated with NaOHaq. to remove the soldering mask. Experiments were performed in acidic medium (HF, H2SO4, CH3COOH or H3PO4) using H2O2 as oxidant. Base metals were leached in high yields (>99 wt.%) at ~40 ºC a
Quím. Nova. Publicado em: 20/07/2020
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16. Application of a Chemometric Method to Interpret Spectrophotometric Data Obtained for Degradation of an Organic Dye in Water Using Manganese Oxide
Birnessite type manganese oxide (δ-MnO2) was synthesized for use in degradation of the cationic dye methylene blue in aqueous solution. The material was characterized using infrared spectroscopy, X-ray diffraction, and Brunauer-Emmett-Teller (BET) surface area calculations. The removal of the dye from aqueous solutions was evaluated considering the effects
J. Braz. Chem. Soc.. Publicado em: 2020-07
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17. Errata
Birnessite type manganese oxide (δ-MnO2) was synthesized for use in degradation of the cationic dye methylene blue in aqueous solution. The material was characterized using infrared spectroscopy, X-ray diffraction, and Brunauer-Emmett-Teller (BET) surface area calculations. The removal of the dye from aqueous solutions was evaluated considering the effects
Ambient. constr.. Publicado em: 2020-07
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18. SPECIATION ANALYSIS OF ARSENIC IN RICE USING HIGH PERFORMANCE LIQUID CHROMATOGRAPHY COUPLED WITH HYDRIDE GENERATION ATOMIC FLUORESCENCE SPECTROMETRY (HPLC-HG-AFS)
The aim of this work was to develop a method using high performance liquid chromatography coupled with hydride generation atomic fluorescence spectrometry (HPLC-HG-AFS) for the determination and speciation analysis of the inorganic and organic species of arsenic found most often in rice samples: As(V), As(III), monomethylarsonic acid (MMA), and dimethylarsin
Quím. Nova. Publicado em: 2020-06
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19. THEORETICAL STUDIES ON DIACETONEDIPEROXIDE DERIVATIVES AND COMPARISONS WITH OTHER MULTI-PEROXIDIC COMPOUNDS
Diacetonediperoxide (DADP) derivatives were investigated with density functional theory (DFT) methods at the DFT-B3LYP and M06-2X/6-311++G (d, p) levels and were also compared with other multi-peroxidic compounds. The investigated derivatives were 3,6-dimethyl-3,6-diamine-1,2,4,5-tetraoxane (DADPNH2), 3,6-dimethyl-3,6-dinitro-1,2,4,5-tetraoxane (DADPNO2), an
Quím. Nova. Publicado em: 2020-06
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20. PREPARAÇÃO DE HIDRAZONA E N-ACILIDRAZONA USANDO FÁRMACOS COMERCIAIS COMO REAGENTES: AULAS PRÁTICAS DE SÍNTESE DE COMPOSTOS BIOATIVOS
Several scientific works demonstrate the chemical and medicinal importance of hydrazone compounds. In this regard, the present paper proposes some practical classes of chemoinformatics and organic chemistry, using investigative and illustrative strategies, to teach the synthesis of a hydrazone and a N-acylhydrazone with proven biological activity. The motiva
Quím. Nova. Publicado em: 2020-05
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21. Chemically-Activated Biochar from Ricinus communis L. Cake and Their Potential Applications for the Voltammetric Assessment of Some Relevant Environmental Pollutants
Biochar is a rich-carbon material highly functionalized, which allows the use as electrodes modifier for preconcentration and voltammetric determination of several species. This work describes a castor cake biochar production and chemical activation with different reaction conditions using HNO3 and/or H2O2. Biochar samples were characterized using scanning e
J. Braz. Chem. Soc.. Publicado em: 2020-05
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22. CONCEPTS, INTENTIONS AND MATERIAL OBJECTS. SOME COMMENTS ON EVNINE’S PROPOSAL IN MAKING OBJECTS AND EVENTS
Abstract In this paper I present and critically discuss Simon Evnine’s account of hylomorphically complex objects (as presented in his 2016 book Making Objects and Events). On the one hand, I object to the account he gives of how artifacts (which are for him the paradigmatic cases of hylomorphically complex objects) allegedly acquire their existence and id
Manuscrito. Publicado em: 2020-03
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23. COMPLEXO ESTUARINO LAGUNAR MUNDAÚ-MANGUABA: CARACTERIZAÇÃO DA MATÉRIA ORGÂNICA NATURAL E INTERAÇÃO COM ÍONS Hg2+
The Mundaú-Manguaba lagoon estuary complex is the most important ecosystem in the state of Alagoas, and a source of sustenance for a large number of the state’s inhabitants. However, degradation by anthropic sources has been causing impacts on this ecosystem. Understanding the characteristics of the natural organic material of the waters of the mundaú-ma
Quím. Nova. Publicado em: 2020-02
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24. PMMA-SiO2 Organic-Inorganic Hybrid Coating Application to Ti-6Al-4V Alloy Prepared through the Sol-Gel Method
Siloxane-poly(methyl methacrylate) (PMMA) hybrid was synthesized based on the sol-gel method and applied to Ti-6Al-4V through dip-coating. The structural feature of the hybrid was subjected to Fourier-transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TG); its morphological properties were analyzed through scanning electron microscope (SE
J. Braz. Chem. Soc.. Publicado em: 2020-02