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Mostrando 1-12 de 378 artigos, teses e dissertações.
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1. Use of graphite in the distribution of rice seeds with constant flow seed metering device
RESUMO O desempenho do mecanismo dosador de semente é avaliado de acordo com a uniformidade da deposição ao longo da operação e sua interferência na qualidade das sementes. O objetivo do experimento foi avaliar a influência da utilização do grafite, na homogeneidade de deposição e no índice de quebras das sementes de arroz, distribuídas com dosa
Revista Brasileira de Engenharia Agrícola e Ambiental. Publicado em: 2023
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2. Development of a ceramic membrane for emulsion water-diesel treatment
Abstract The purpose of this study was the development of a low-cost ceramic tubular membrane, using inexpensive materials, namely natural clay, and graphite as a porogenic agent. Such a low-cost membrane can be used as filters or porous supports for the preparation of multilayer ceramic membranes. Extrusion was used as a shape-forming method for this purpos
Cerâmica. Publicado em: 2022
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3. Graphite-Polyurethane Composite Electrode Modified with Molecularly Imprinted Polymer for Determination of Diclofenac
A molecularly imprinted polymer (MIP) was prepared using the anti-inflammatory diclofenac (DCF) as a template. A non-imprinted polymer (NIP) was also prepared as a control. These MIP and NIP were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Brunauer-Emmett-Teller (BET), revealing a higher porosity in the fir
Journal of the Brazilian Chemical Society. Publicado em: 2022
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4. A New Synthetic Route and Comprehensive Topological Study of a Benzimidazole Derivative
Benzimidazole and its derivatives are molecules that have diverse biological properties, therefore we synthesized and studied a new benzimidazole to understand their physical/chemical properties. The compound was obtained through a new synthetic route, using graphite oxide, in the absence of solvent, with crystalline packaging supported by C-H…N and C-H…
Journal of the Brazilian Chemical Society. Publicado em: 2022
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5. Simple Spectrophotometric Determination of Iron in Diesel Oil after Sample Preparation Employing Extraction Induced by Emulsion Breaking
This work reports the development of a simple and fast method for the spectrophotometric determination of Fe in diesel oil using the classic reaction with 1,10-phenanthroline after its extraction induced by emulsion breaking (EIEB). The extraction parameters of EIEB were optimized (concentration of HNO3 and Triton X-100® in the emulsifying solution) as well
Journal of the Brazilian Chemical Society. Publicado em: 2022
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6. Dispersive Solid-Phase Extraction Using 3-Mercaptopropyltrimethoxysilane Functionalized Magnetic MWCNT-Based Nanocomposite for Selective and Efficient Preconcentration of Pb2+ with FAAS Determination
A novel nanocomposite based on magnetic multiwalled carbon nanotubes coated with SiO2 and functionalized with 3-mercaptopropyltrimethoxysilane (3-MPTMS) was prepared for the efficient extraction and quantification of lead ions from water samples. The adsorption capacity of this adsorbent could reach 1.995 mg g-1 Pb2+ in an equilibrium time of 30 min. Under o
Journal of the Brazilian Chemical Society. Publicado em: 2022
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7. On the Use of a TiO2 Sol-Gel for Horseradish Peroxidase Enzyme Immobilization for Development of an Amperometric Biosensor
The sol-gel technique has drawn considerable attention in the area of biomolecules immobilization by virtue of its intrinsic properties including chemical inertness, thermal stability, and good biocompatibility. The present work reports the development of a bio-sensing methodology which involves the immobilization of horseradish peroxidase enzyme (HRP) on pe
J. Braz. Chem. Soc.. Publicado em: 2021-06
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8. Development of a Methodology Based on Extraction Induced by Emulsion Breaking for Copper Determination in Gasohol by Graphite Furnace Atomic Absorption Spectrometry
The development of a method based on extraction induced by emulsion breaking (EIEB) aiming copper determination in gasohol using graphite furnace atomic absorption spectrometry (GF AAS) is reported. Emulsification of the gasohol samples was carried out using nitric acid solution, (1,1,3,3-tetramethylbutyl)phenyl-polyethylene glycol surfactant (Triton X-114),
J. Braz. Chem. Soc.. Publicado em: 2021-02
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9. AVALIAÇÃO DE NANOTUBOS DE CARBONO FUNCIONALIZADOS VISANDO O DESENVOLVIMENTO DE MÉTODOS DE PRÉ-CONCENTRAÇÃO DE ÍONS METÁLICOS E DETERMINAÇÃO POR TÉCNICAS ESPECTROMÉTRICAS E ELETROANALÍTICAS
This review focuses on the use of functionalized carbon nanotubes (CNTs) on the development of preconcentration methods with substantial contributions on selectivity and sensitivity for metal ions determination. CNTs have been usually employed in the development of preconcentration/speciation coupled to spectroanalytical techniques for ions determination at
Quím. Nova. Publicado em: 2020-09
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10. Determination of Copper and Cadmium in Petroleum Produced Formation Water by Electrothermal Atomic Absorption Spectrometry after Cloud Point Extraction
Cloud point extraction (CPE) in association with graphite furnace atomic absorption spectrometry (GF AAS) was proposed for preconcentration and quantification of trace amounts of copper and cadmium in samples of saline produced formation water from petroleum exploration. The procedure was based on the formation of hydrophobic complexes of the analytes with 1
J. Braz. Chem. Soc.. Publicado em: 2020-06
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11. Simple GFAAS Method for Determination of Pb, As, and Cd in Cannabidiol Extracts Used for Therapeutic Purposes
Cannabis sativa has many promising medicinal applications for the mitigation, or even cure, of chronic diseases. The high bioaccumulation potential of C. sativa enables its use for the phytoremediation and detoxification of soil, may increase the levels of inorganic elements in products such as cannabidiol (CBD) extracts being necessary the evaluation/monito
J. Braz. Chem. Soc.. Publicado em: 2020-05
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12. Evaluation of a Graphite-Polyurethane Composite Electrode Modified with Copper Nanoparticles as an Amperometric Flow Detector in a Wall-Jet System for the Determination of Cysteine
A graphite-polyurethane composite electrode (GPUE) was modified by electrodeposition of copper nanoparticles (CuNP) followed by electrochemical treatment in NaOH (GPUE-CuNP), in order to prepare an amperometric sensor for the determination of cysteine (Cys). Cyclic votammograms of Cys solutions at GPUE-CuNP allowed the description of a sequence of electroche
J. Braz. Chem. Soc.. Publicado em: 2020-02