Microwave Irradiation
Mostrando 1-12 de 90 artigos, teses e dissertações.
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1. Expansibility of vermiculite (Santa Luzia, Brazil) irradiated with microwave
Abstract The effect of microwave heating on the expansion of vermiculite was studied at a level of 700 W for 4 min exposure time and compared with raw vermiculite. In this study, the characterization of vermiculite from a mine in the northeast region of Brazil was performed using thermogravimetry, N2-adsorption, cation exchange capacity, X-ray powder diffrac
Cerâmica. Publicado em: 2021-06
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2. Antibacterial Activity of 2-Amino-1,4-naphthoquinone Derivatives against Gram-Positive and Gram-Negative Bacterial Strains and Their Interaction with Human Serum Albumin
A series of 2-amino-1,4-naphthoquinone derivatives (NQA-NQF) was synthesized by alternative methods (ultrasonication and microwave irradiation), with yields ranging from 40 to 71%, and without the need of further recrystallization. Each compound was evaluated against four Gram-positive (Bacillus subtilis, Enterococcus faecalis, Staphylococcus aureus and Baci
J. Braz. Chem. Soc.. Publicado em: 2020-09
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3. Microwave Assisted Synthesis of Thiocarbamoylpyrazoles and Application as an Alternative Latent Fingermark Developers
Fingerprints are unique to each individual, contributing to human identification in forensic cases. The powder technique being widely used is considered one of the most important in latent fingermarks analysis. In this sense, the present work aimed to synthesize 1-thiocarbamoyl-4,5-dihydro-1H-pyrazoles and apply them as powder agents to develop latent finger
J. Braz. Chem. Soc.. Publicado em: 2020-06
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4. A RENEWABLE CATALYST FOR A RENEWABLE CHEMICAL: GRAM-SCALE CONVERSION OF FURFURAL TO FURFURYL ALCOHOL BY THE CARROT (Daucus carota)
The bioconversion of furfural to furfuryl alcohol using only carrot bits in water at room temperature and ambient pressure is presented. This reaction led to the bioreduction of furfural with 99% conversion and 99% selectivity to an alcohol. This simple and “fully” green process may represent an alternative to classic hydrogenation processes. Also, witho
Quím. Nova. Publicado em: 2020-01
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5. Recovery of chitin and chitosan from shrimp waste with microwave technique and versatile application
RESUMO: Neste estudo, a quitina e a quitosana foram extraídas de resíduos de Litopenaeus vannamei utilizando métodos químicos e do micro-ondas. Os resíduos de camarão foram limpos, secos e peneirados a 16, 32 e 60 mesh, e as amostras foram despigmentadas, desmineralizadas e desproteinizadas. Posteriormente, a quitina foi submetida a processo de desacet
Arq. Inst. Biol.. Publicado em: 28/10/2019
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6. Design, Synthesis, Trypanocidal Activity, and Studies on Human Album in Interaction of Novel S-Alkyl-1,2,4-triazoles
Chagas disease is a neglected tropical disease caused by the hemoflagellated parasite Trypanosoma cruzi (Kinetoplastida). The only available drug to treat chagasic patients in Brazil, the nitroheterocycle benznidazole, is effective solely during the acute phase of the infection. There is accordingly a need to develop new therapeutic tools for the treatment o
J. Braz. Chem. Soc.. Publicado em: 04/07/2019
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7. Ketalization of Ketones to 1,3-Dioxolanes and Concurring Self-Aldolization Catalyzed by an Amorphous, Hydrophilic SiO2-SO3H Catalyst under Microwave Irradiation
The amorphous, mesoporous SiO2-SO3H catalyst with a surface area of 115 m2 g-1 and 1.32 mmol H+ per g was very efficient for the protonation of ketones on a 10% (m/m) basis, and the catalyst-bound intermediates can be trapped by polyalcohols to produce ketals in high yields or suffer aldol condensations within minutes under low-power microwave irradiation. T
J. Braz. Chem. Soc.. Publicado em: 2018-08
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8. Improved Method for Microwave-Assisted Synthesis of Benzodiazepine-2,5-diones from Isatoic Anhydrides Mediated by Glacial Acetic Acid
An improved and simpler method for the synthesis of benzodiazepin-2,5-diones and 7-iodobenzodiazepin-2,5-diones catalyzed by glacial acetic acid using isatoic anhydride and 6-iodoisatoic anhydride, respectively, as starting materials is reported. The target products were achieved in good yields (up to 71%) using microwave irradiation as the activating mode o
J. Braz. Chem. Soc.. Publicado em: 2018-08
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9. Effect of disinfection techniques on physical-mechanical properties of a microwave-activated acrylic resin
Abstract The effects of disinfection by microwave irradiation and immersion in peracetic acid on the physical-mechanical properties of a microwave-activated acrylic resin were evaluated. Specimens of acrylic resin were divided into a control group (specimens not disinfected) and 2 test groups subjected to one disinfection method: microwave irradiation at 85
Polímeros. Publicado em: 06/07/2018
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10. Long-term microwaving of denture base materials: effects on dimensional, color and translucency stability
Abstract While the combined effect of microwave irradiation with cleansing solutions on denture base materials has been investigated, the effects of only using microwave irradiation and, more importantly, in a long-term basis, was not studied yet. Objective The purpose of this study was to evaluate the effect of a long-term repeated microwaving on the dime
J. Appl. Oral Sci.. Publicado em: 18/06/2018
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11. Preparation of Nickel Ferrite/Carbon Nanotubes Composite by Microwave Irradiation Technique for Use as Catalyst in Photo-Fenton Reaction
Nickel ferrite/multi-walled carbon nanotubes (NiFe2O4/MWCNTs) composite has been rapidly synthesized via microwave irradiation technique. The structural properties of the product was investigated by X-ray diffraction (XRD), N2 adsorption/desorption isotherms, thermogravimetric analysis (TGA), Raman spectroscopy and, scanning electron microscopy (SEM). Cataly
Mat. Res.. Publicado em: 03/08/2017
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12. Influence of microwave irradiation on kinetics and thermodynamics of extraction of flavonoids from Phyllanthus emblica
Abstract-The effects of solvent-to-feed (S) and temperature (T) on the kinetics and thermodynamics of the microwave assisted extraction (MAE) of flavonoids from dried fruits of Phyllanthus emblica using water as solvent have been studied. The flavonoid concentration - time data was analyzed using second order and diffusion models. Both the temperature and so
Braz. J. Chem. Eng.. Publicado em: 2017-07