Efficient
Mostrando 13-24 de 15592 artigos, teses e dissertações.
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13. Heteroannulation Reaction of α-Aminoketones for the Efficient Synthesis of 4-Imidazolin-2-ones and 2-Thiones
The hydrogenation of α-oximinoketones in methanol/HCl afforded α-aminoketones, which were applied without purification to the synthesis of 4-imidazolin-2-ones and 2-thiones, including chiral derivatives. The latter two series were obtained in high yields by a heteroannulation reaction of α-aminoketones with isocyanates and isothiocyanates, respectively. A
Journal of the Brazilian Chemical Society. Publicado em: 2022
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14. Synthesis of Conjugated Molecules Based on Dithienopyrrole Derivatives and Pyrene as Chemosensor for Mesotrione Detection
The conjugated molecules based on pyrene and dithienopyrrole derivatives including 4-(2-ethylhexyl)-2-(pyren-1-yl)-4H-dithieno[3,2-b:2’,3’-d]pyrrole (EP4HP) and 4-(2-ethylhexyl)-2,6-di(pyren-1-yl)-4H-dithieno[3,2-b:2’,3’-d]pyrrole (EDP4HP) have been successfully synthesized via C-H direct arylation reaction. The structures of these conjugated molecul
Journal of the Brazilian Chemical Society. Publicado em: 2022
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15. TESTES DIAGNÓSTICOS PARA O SARS-COV-2: UMA REFLEXÃO CRÍTICA
The new coronavirus, called Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), was discovered in late December 2019 after cases were reported in the city of Wuhan, China. In January 2020, the World Health Organization (WHO) officially declared the Coronavirus Disease 2019 (COVID-19) as a pandemic, which has an official record of around 500 million
Química Nova. Publicado em: 2022
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16. Growth dynamics of container seedlings of Eucalyptus grandis x Eucalyptus urophylla and Hymenaea courbaril L.
ABSTRACT Growth analysis (GA) is used to quantify plant development based on morphophysiological changes. GA is a practical tool to evaluate nursery techniques to make them more efficient. The objective of this essay was to quantity measure morphophysiological growth variables of Eucalyptus grandis x Eucalyptus urophylla and Hymenaea courbaril (jatoba) conta
Revista Ceres. Publicado em: 2022
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17. Sustainable and Reusable Sulfonic Acid-Functionalized Task-Specific Ionic Liquid Catalysts for Multicomponent Reactions. A Review
Improvements in Sustainable Organic Synthesis are usually related to the investigation of less hazardous, non-corrosive and renewable materials, as well as waste prevention, energy efficiency, solvent-free reactions, and the development of efficient reusable catalysts. In this context, multicomponent reactions emerged as important strategies for the rapid an
Journal of the Brazilian Chemical Society. Publicado em: 2022
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18. Mechanical properties and fractography of cement-based composites reinforced by natural piassava and jute fibers
Abstract Today’s demand for environmentally friendly and energy-efficient solutions to the construction industry has driven researchers to match natural resources with traditional technics to develop new building technologies. However, there are literature limitations about the correlation of fiber-matrix interface with the failure of natural fibers in mor
Cerâmica. Publicado em: 2022
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19. Tandem Synthesis of Furanaphthoquinones via Enamines and Evaluation of Their Antiparasitic Effects against Trypanosoma cruzi
Furanaphthoquinones are well known in medicinal chemistry for exhibiting relevant structural heterogeneity and bioactivities. In this work, it was synthesized a series of furanaphthoquinones through a tandem reaction between lawsone (8) and cyclic ketones in the presence of morpholine. This strategy provides an efficient and general method for synthesizing f
Journal of the Brazilian Chemical Society. Publicado em: 2022
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20. Efficient Low-Complexity Optimized Channel Estimating Methods for OFDM-Based Low-Voltage Broadband Power Line Communication Systems
Abstract Broadband Power Line Communication (BB-PLC) technology enables data transmission for smart grid applications. Nevertheless, channel equalizers are required in the receiver to estimate and compensate for the nonlinear time-variant impulse response and noise interference effects introduced by the BB-PLC channel. In this paper, we append the Particle S
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2022
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21. ADSORPTION OF ATRAZINE IN RICE HUSK BIOCHARS: A PHENOMENOLOGICAL MODEL APPLIED TO EQUILIBRIUM AND KINETIC STUDIES
ABSTRACT Atrazine is an herbicide used to remove weeds in agricultural crops; however, because it is considered toxic, options for removing it from the environment are needed. Adsorption on biochar is an efficient technique for removing organic contaminants. In this study, the atrazine adsorption capacities of two biochars (BCA400 and BCA700) produced from r
Engenharia Agrícola. Publicado em: 2022
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22. Diacetate Naphthoquinone Derivatives Tethered to 1,2,3-Triazoles: Synthesis and Cytotoxicity Evaluation in Caco-2 Cells
Acetylated compounds prepared from naphthoquinones have been reported as antitumoral prodrugs. Exploring the synthetic versatility of the naphthoquinone and triazolic nuclei, herein we report a simple and efficient synthetic route to prepare a series of sixteen prodrugs prototype of 1,2,3-triazoles-naphthoquinodoic acetyl derivatives. The compounds 10a-10h a
Journal of the Brazilian Chemical Society. Publicado em: 2022
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23. Per-Aqueous Liquid Chromatography for the Separation of Polar Compounds Preparation and Characterization of Poly(ethylene oxide co dimethylsiloxane) Based Stationary Phase
Poly(ethylene oxide-co-dimethylsiloxane) was thermally immobilized on silica particles-Si(PEO)-to separate small polar compounds with water-rich mobile phases. Poly(ethylene oxide-co-dimethylsiloxane) content on Si(PEO) stationary phase was optimized using a central composite design. Infrared spectroscopy, scanning electron microscopy, and thermogravimetric
Journal of the Brazilian Chemical Society. Publicado em: 2022
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24. Study of electrophoretic deposition of ZnO photoanodes on fluorine-doped tin oxide (FTO) glass for dye-sensitized solar cells (DSSCs)
Abstract Semiconductors, such as zinc oxide (ZnO), are used in different scientific fields, including energy. This study applied ZnO thin films on a photovoltaic cell, specifically a dye-sensitized solar cell (DSSC). ZnO was used in solar cells due to its characteristics such as electronic mobility. Electrophoretic deposition (EPD) is an efficient method to
Cerâmica. Publicado em: 2022