Chemical Modification
Mostrando 1-12 de 712 artigos, teses e dissertações.
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1. Study of Catalytic Pyrolysis of Biomass Sorghum (Sorghum bicolor L. Moench) Using Design of Experiments and Surface Response Methodology
This study proposes a screen of variables that have an influence on the modification of the bio-oil chemical composition as a unique critical quality attribute (CQA) throughout the pyrolytic process (zeolite, ZSM-5) by using a 24 full factorial design, followed by optimization through a response surface methodology (RSM) based on central composite design (CC
Journal of the Brazilian Chemical Society. Publicado em: 2023
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2. Gold Nanorods Capped with Different Ammonium Bromide Salts on the Catalytic Chemical Reduction of p-Nitrophenol
It is known that the reactivity of the nanocatalytic systems is related to the particle size and shape and also to the features of the capping agents on the nanostructures. In this study, gold nanorods (AuNRs) were synthesized by the seed-mediated method using different tetra-alkylammonium bromide salts as capping agents, that are, cetyltrimethylammonium (CT
J. Braz. Chem. Soc.. Publicado em: 2021-06
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3. The importance of education
Abstract The present research is dedicated to analyzing the addition of sawdust biomass, which is a carbonaceous raw material that may be used in coal blends for the production of metallurgical coke, preserving the required quality, with lower cost. The quality of metallurgical coke may be determined by the efficiency of its chemical, physical and thermal fu
REM, Int. Eng. J.. Publicado em: 2021-06
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4. Quality evaluation of metallurgical coke produced with sawdust and different mixtures of coal
Abstract The present research is dedicated to analyzing the addition of sawdust biomass, which is a carbonaceous raw material that may be used in coal blends for the production of metallurgical coke, preserving the required quality, with lower cost. The quality of metallurgical coke may be determined by the efficiency of its chemical, physical and thermal fu
REM, Int. Eng. J.. Publicado em: 2021-06
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5. Acid matrix production from treated natural vermiculite-hydrobiotite
Abstract Given the potential of acid-activated clays in adsorptive and catalytic processes, several studies focusing on acid matrices have grown over the years, making it possible to study vermiculite, a mineral composed of a type 2:1 unit cell with tetrahedral and octahedral sheets. Therefore, this work aimed to study vermiculite treated with acids for the
Cerâmica. Publicado em: 2021-06
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6. MODIFICAÇÃO QUÍMICA DO POLIPROPILENO ATRAVÉS DA INTRODUÇÃO DE GRUPOS SULFÔNICOS PARA APLICAÇÃO COMO CATALISADOR EM REAÇÕES DE ESTERIFICAÇÃO
In this work, the chemical modification of pristine polypropylene was carried out through sulfonation reactions with concentrated sulfuric acid (PPS1) and fuming sulfuric acid (PPS2), for production of heterogeneous catalysts used in esterification reactions. Fourier transform infrared spectroscopy, elemental analysis, degree of substitution and ion exchange
Quím. Nova. Publicado em: 2021-04
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7. BEHAVIOR OF THERMALLY MODIFIED WOOD TO BIODETERIORATION BY XYLOPHAGE FUNGI
ABSTRACT Thermally modified wood undergoes chemical, physical, and mechanical modifications, resulting in changes in resistance to wood biodegrading agents. The objective of this study was to evaluate the resistance to biodeterioration of thermally modified wood by the industrial process VAP HolzSysteme® of Eucalyptus grandis, Pinus taeda and Tectona grandi
CERNE. Publicado em: 2020-09
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8. 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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9. STABILIZATION STUDY OF TETRAMERIC Kluyveromyces lactis β-GALACTOSIDASE BY IMMOBILIZATION ON IMMOBEAD: THERMAL, PHYSICO-CHEMICAL, TEXTURAL AND CATALYTIC PROPERTIES
Abstract We investigated the immobilization of a tetrameric Kluyveromyces lactis β-galactosidase (EC: 3.2.1.23) (KL-Gal) on Immobead 150 using different support modification strategies. Immobead support was modified using an acid solution of H2SO4:HNO3 (3:1) (Immobead-Ac) or 5 % (v/v) glutaraldehyde (Immobead-Glu). Its unmodified form (Immobead) was also te
Braz. J. Chem. Eng.. Publicado em: 13/01/2020
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10. SISTEMAS PEDOGEOMORFOLÓGICOS NA INTERPRETAÇÃO DA EVOLUÇÃO DE PAISAGENS QUATERNÁRIAS EM CLIMAS TROPICAIS ÚMIDOS
Resumo As relações entre solo e relevo são constantes em paisagens de climas tropicais e subtropicais úmidos, devido aos espessos mantos regolíticos resultantes de acelerado intemperismo físico, químico e biológico. A investigação dos sistemas pedogeomorfológicos merece destaque em análises sistêmicas, que objetivam o estudo da gênese e dos pro
Mercator (Fortaleza). Publicado em: 09/12/2019
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11. Modification of Chitosan by Zincke Reaction: Synthesis of a Novel Polycationic Chitosan-Pyridinium Derivative
Chitosan is a biodegradable aminopolysaccharide produced by deacetylation of acetamide groups of chitin, one of the most abundant organic materials in nature. Many different types of organic reactions have been described to modify the functional groups of chitosan and produce materials with applications in a large number of areas. However, the Zincke reactio
J. Braz. Chem. Soc.. Publicado em: 24/10/2019
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12. Síntesis y caracterización de un novedoso biomaterial a base de quitosano modificado con aminoácidos
ABSTRACT The chemical modification of chitosan (CH) from shrimp shells (Litopenaeus vannamei) was performed with amino acids: L-leucine (Leu) and L-tyrosine (Tyr), in order to change some of its physical and chemical properties, which allow the enhancement of the applications of chitosan in biomedical and pharmacological areas. The characterization of chitos
Matéria (Rio J.). Publicado em: 16/09/2019