X Ray Fluorescence
Mostrando 1-12 de 412 artigos, teses e dissertações.
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1. Carbon Dots from Pilosocereus gounellei for Fluorimetric Determination of Tannin in Tea Using a Flow-Batch System
In this study, xiquexique (Pilosocereus gounellei) native endemic cactus from the Brazilian semiarid was used for the first time as a natural carbon source (“green precursor”) for the synthesis of highly fluorescent carbon dots (CDs). These CDs were successfully used to develop a fast, low-cost, eco-friendly fluorescence method for the determination of t
Journal of the Brazilian Chemical Society. Publicado em: 2023
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2. A química analítica aplicada aos estudos de pigmentos rupestres: uma revisão
Instrumental advances have been employed in the study of archeological remains such as prehistoric rupestrians paintings with the objective of chemically characterizing them in order to reconstruct the cultural technologies of a prehistoric human group and/or to support conservation science studies. The analytical techniques most commonly used in archaeometr
Química Nova. Publicado em: 2022
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3. The influence of separately and combined bentonite and kaolinite as binders for pelletization of NaA zeolite from coal fly ash
Abstract Pelletization of zeolitic materials is required to facilitate their practical industrial and commercial applications. Zeolite-NaA was synthesized from fly ash by the fusion method and shaped into spherical granules. Bentonite, kaolinite, and a combination of bentonite with kaolinite were tested as binders with different contents from 5 to 10 wt%. Th
Cerâmica. Publicado em: 2022
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4. Characterization of Commercially Available Turmeric for Use in Pharmaceutical Products and Food Supplements
We addressed some physicochemical and biological differences in commercial turmeric, acquired from both handling pharmacies and stores selling natural products for quality assessment. For this, it was determined the melting point, antioxidant activity by 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH), antimicrobial activity via the agar disk-diffusion assay,
Journal of the Brazilian Chemical Society. Publicado em: 2022
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5. CLOROFILA EXTRAÍDA DE RESÍDUO INDUSTRIAL DA ERVA-MATE (Ilex paraguaiensis) UMA POSSIBILIDADE DE ECONOMIA CIRCULAR
Chlorophyll is the most abundant green pigment on the planet, it is unstable and decomposes naturally. Mate-herb is a traditional native plant in the southern region of South America, and its tea is part of the local culture and extractive agriculture. The mate-herb industry generates as a by-product a resinous material rich in chlorophyll whose use is propo
Química Nova. Publicado em: 2022
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6. Photo-Fenton-Based Degradation of Methylene Blue Dye Using Hydroxyapatite Nanoparticles Doped with Fe3O4/γ-Fe2O3
In this study, we evaluated the catalytic properties of hydroxyapatite (HA) nanoparticles (NPs) doped with Fe3O4/γ-Fe2O3 for the degradation of methylene blue (MB) dye using a photo-Fenton process at pH 2.5, 7.0, and 9.0. The HA NPs were characterized using X-ray diffraction, scanning electron microscopy, Fourier-transform infrared spectrometry, Raman spect
Journal of the Brazilian Chemical Society. Publicado em: 2022
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7. 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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8. Purification of raw palygorskite: a comparative study involving different processes and dispersing agents
Abstract Palygorskite (Pal) is a natural clay mineral with fibrous morphology and high surface area. Depending on the geological origin, it presents impurities, such as quartz and carbonates, which can harm some of its properties. Therefore, this work seeks to define a viable methodology for the purification of a Brazilian Pal. Two types of mixing processes
Cerâmica. Publicado em: 2021-06
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9. 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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10. Incorporation of Fluorescent Dyes in Electrospun Chitosan/Poly(ethylene oxide)
Polymeric films have been increasingly investigated due to the ease of miniaturization and integration in several sensor devices. Films obtained from the electrospinning technique have a controlled diameter and homogeneity, and substances can be incorporated into the polymeric network. Electrospinning fiber of chitosan (Ch) and poly(ethylene oxide) (PEO) was
J. Braz. Chem. Soc.. Publicado em: 2021-05
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11. Synthesis and characterization of niobium-doped fish scale-derived hydroxyapatite by physical ultrasound interference
Abstract Fish scales of the Arapaima gigas (pirarucu) species were heat-treated to obtain natural hydroxyapatite (HAp), and it was doped with niobium (Nb) by physical ultrasound interference to confirm an effective route to the production of Nb-doped HAp powders. The effect of ultrasound application on doping was investigated. The structure of the powders wa
Cerâmica. Publicado em: 2021-03
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12. DETERMINAÇÃO DE FÓSFORO EM PALEOSSEDIMENTOS EMPREGANDO ESPECTROMETRIA DE FLUORESCÊNCIA DE RAIOS-X PORTÁTIL
Phosphorus (P) is an important chemical marker of the past human presence, because, besides indicates the localization of possible archaeological sites, also, contributes to clarify doubts regarding to origin, duration and to specific functions that were developed in them. The present study aimed to obtain a simple, accurate, fast and non-destructible analyt
Quím. Nova. Publicado em: 2021-02