Microwave Oven
Mostrando 1-12 de 117 artigos, teses e dissertações.
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1. Atomic Absorption Spectrometry as an Alternative to Determine the Presence of Gold Nanoparticles on or in Silica Matrix
Two different gold-silica-based nanomaterials were prepared: (i) silica-supported gold nanoparticles (AuNP/SiO2); and (ii) gold-silica core-shell nanoparticles (AuNP@SiO2). Three strategies for sample treatment (S), consisting in acid treatments, were employed: (S1) HNO3; (S2) HNO3 + HCl; and (S3) HF + HNO3 + HCl, applying microwave oven digestion for S2 and
Journal of the Brazilian Chemical Society. Publicado em: 2022
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2. Green Synthesis of Upconverting NaYF4 and NaGdF4 Materials and Energy Levels Determination
An alternative green route using a domestic microwave oven to synthesize NaGdF4:Yb,Tm and NaYF4:Yb,Er was successfully developed. Decreasing dopants concentration increased the β-NaREF4/α-NaREF4 ratio in NaGdF4. The scanning electron microscopy (SEM) images of NaGdF4 showed particles ranging from 500 nm to 1 μm with formation of aggregates up to 100 μm,
J. Braz. Chem. Soc.. Publicado em: 2021-08
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3. Quantification of Arsenic, Cadmium, Mercury and Lead in Pineapple: Method Development, Validation and Evaluation of In-House Reference Materials
A method for quantification of arsenic, cadmium, mercury, and lead in pineapple using inductively coupled plasma-mass spectrometry (ICP-MS) was developed, validated, and used to test the homogeneity and stability of in-house reference materials. The method was tested at the regulation levels given by the Food and Agriculture Organization of the United Nation
J. Braz. Chem. Soc.. Publicado em: 2020-06
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4. Simple and Low-Cost Thermal Treatments on Direct Resin Composites for Indirect Use
Resumo O objetivo deste estudo foi avaliar a influência de três tratamentos térmicos adicionais de baixo custo, disponíveis no consultório dentário, nas propriedades mecânicas, químicas e ópticas de uma resina composta fotoativada indicada para restaurações diretas porém usada como restaurador indireto. A resina composta direta TPH3 (Dentsply) fo
Braz. Dent. J.. Publicado em: 03/06/2019
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5. COMPARAÇÃO ENTRE TÉCNICAS DE EXTRAÇÃO DE HIDROCARBONETOS POLICÍCLICOS AROMÁTICOS EM TECIDOS HEPÁTICO E ADIPOSO DE TETRÁPODES MARINHOS E AVALIAÇÃO DA HETEROGENEIDADE DOS TECIDOS
For the evaluation of PAH extraction techniques in adipose and liver tissues of marine tetrapod, samples of some species (Pontoporia blainvillei, Chelonia mydas, Thalassarche melanophris, and Balaenoptera brydei) were spiked with PAH standards and extracted using soxhlet system and microwave oven. The results of both extraction techniques for the two differe
Quím. Nova. Publicado em: 2019-02
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6. Development of a microwave absorbing material based on molybdenum-doped niobium pentoxide
Abstract This work aimed to perform the characterization of electrical properties of niobium pentoxide, Nb2O5, pure and doped with molybdenum, prepared by powder metallurgy route and to do a comparative analysis of the influence of this material when sintered in a muffle or in a microwave oven. The results showed that the doping of the niobium pentoxide with
Cerâmica. Publicado em: 2019-01
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7. EXPERIMENTO COM ABACATE, BORRA DE CAFÉ, LICURI E LEITE DE COCO PARA EXTRAÇÃO DE ÓLEO, PRODUÇÃO DE BIODIESEL E ANÁLISE ESPECTRAL
An undergraduate organic chemistry experiment for oil extraction and biodiesel production using alternative biomass was developed, whereby oils of avocado, coconut and spent coffee grounds were obtained and submitted to transesterification reaction with CH3OH under NaOH catalysis. Avocado and coffee oils were obtained by typical extraction and coconut oil wa
Quím. Nova. Publicado em: 2018-06
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8. Chemical compositions and antioxidant activity of Heracleum persicum essential oil
ABSTRACT In this study essential oil of the aerial parts of Heracleum persicum a spice widely used in Iran was isolated by conventional hydrodistillation (HD) and microwave-assisted hydrodistillation (MAHD) techniques. The extraction yield was determined and the chemical compositions of essential oils were identified by the application of gas chromatography/
Braz. J. Pharm. Sci.. Publicado em: 01/02/2018
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9. Method validation for determination of metals in Vitis labrusca L. grapevine leaf extracts by inductively coupled plasma mass spectrometry (ICP-MS)
ABSTRACT Vitis labrusca L. is the main species used for wine and juice production in Brazil. The grapevine leaves can be used both as functional foods and as cheapest sources for the extraction of phenolic compounds. Besides the antioxidant activity, grapevine leaves exhibited significant anti-inflammatory activity. Therefore, the aim of this study was to de
An. Acad. Bras. Ciênc.. Publicado em: 2016-12
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10. Method Development and Total Uncertainty Estimation for Boron, Sulfur and Phosphorus Determination in Mineral Fertilizer Using ICP OES
This study deals with B, S, and P determination in mineral fertilizer and S in commercial sulfur-formulation using inductively coupled plasma optical emission spectrometry. According to multivariate optimization using a Doehlert matrix, the analytes extraction in fertlizer can be conducted in open flask and heating on hot plate or in closed flask in microwav
J. Braz. Chem. Soc.. Publicado em: 2016-11
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11. Physicochemical Characteristics and Lipid Oxidation of Chicken Inner Fillets Subjected to Different Thermal Processing Types
ABSTRACT The objective of this study was to evaluate the effects of different types of thermal processing on the physiochemical characteristics and lipid oxidation of chicken inner fillets. The study was divided into three assays. In the first assay, 50 chicken inner fillets were divided into five treatments, totaling 10 samples per treatment. Treatments con
Rev. Bras. Cienc. Avic.. Publicado em: 2016-09
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12. PREPARAÇÃO DE 1,2,4-OXADIAZOL: SEQUÊNCIA DIDÁTICA APLICADA EM DISCIPLINA DE SÍNTESE ORGÂNICA NA GRADUAÇÃO
1,2,4-oxadiazoles are used in a wide range of applications, including medicinal chemistry and chemistry of materials. However, this kind of oxadiazoles is not usually prepared in an undergraduate organic teaching laboratory. This work describes a didactic sequence for the preparation of 1,2,4-oxadiazols, mediated by microwave irradiation, employing home-use
Quím. Nova. Publicado em: 2016-09