Reflectance Surface
Mostrando 1-12 de 91 artigos, teses e dissertações.
-
1. Catalysts Derived from Thermal Treatments of Hydrocalumite-Type Compounds: Synthesis and Application in Transesterification Reactions
Catalyst performance is a relevant factor in biodiesel production because it can affect the efficiency of the process. This work provides a study of the performance of heterogeneous catalysts for biodiesel production derived from thermal-treated hydrocalumite-type compounds. This work aimed to synthesize and characterize hydrocalumite-type compounds intercal
Journal of the Brazilian Chemical Society. Publicado em: 2023
-
2. Enhancement of Visible Light-Responsive Photocatalytic Efficiency by Using a Laccaic Acid-Modified Titanium Dioxide Photocatalyst
In this study, a laccaic acid-modified TiO2 photocatalyst (Lac-TiO2) was prepared via an impregnation method with 0.50, 1.00, 2.50, and 5.00 wt.% laccaic acid. The products’ physical properties were examined through X-ray powder diffraction (XRD), field emission scanning electron microscopy (FE-SEM), X-ray photoemission spectroscopy (XPS), UV-Vis diffused
Journal of the Brazilian Chemical Society. Publicado em: 2022
-
3. 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
-
4. IN SITU DRIFTS/MS STUDIES ON THE INTERACTION OF METHANOL AND ETHYL ACETATE OVER MG-LA CATALYST
The surface intermediates formed on the Mg-La catalyst (molar ratio 1:1) were studied through temperature-programmed desorption (TPD) and diffuse reflectance infrared Fourier transform spectroscopy coupled to mass spectrometry (DRIFTS-MS) using methanol (MeOH) and ethyl acetate (EA) as probe molecules. TPD results showed that the products formed from adsorbe
Quím. Nova. Publicado em: 2020-09
-
5. Solvothermal Synthesis of Cerium-Doped Titania Nanostructured Materials Modified with Acetylacetone for Solar-Driven Photocatalysis
This study reports the preparation of nanostructured cerium-doped titanium dioxide photocatalysts containing different cerium concentrations by a modified sol-gel route involving the use of acetylacetone. The nanocrystalline powders had their structural, morphological, and optical properties characterized by X-ray diffraction, vibrational and Raman spectrosc
J. Braz. Chem. Soc.. Publicado em: 2020-01
-
6. Hydrogen production from aqueous glycerol using titanate nanotubes decorated with Au nanoparticles as photocatalysts
Abstract: Protonated titanate nanotubes (HTiNts) were synthesized using the hydrothermal method, followed by proton exchange with acid. Gold nanoparticles decorated titanate nanotubes (AuHTiNts) were obtained by the reduction of AuCl4- under vigorous stirring with an aqueous solution of HTiNts containing 1 wt% of ascorbic acid. To investigate the surface str
An. Acad. Bras. Ciênc.. Publicado em: 28/11/2019
-
7. Automatic calibration of a large-scale sediment model using suspended sediment concentration, water quality, and remote sensing data
RESUMO A calibração e a validação são duas etapas importantes na aplicação de modelos de sedimentos que requerem dados observados. Nesse contexto, este estudo investigou o potencial de uso dos dados de concentração de sedimentos em suspensão (CSS), qualidade da água e sensoriamento remoto na calibração e validação de um modelo hidrossedimentol
RBRH. Publicado em: 25/04/2019
-
8. Color stability and surface roughness of chitosan- and nanodiamond-modified bisacrylic resin
Abstract: The aim of this study is to evaluate the effect of chitosan or nanodiamond incorporation on the color stability and surface roughness of a bisacrylic resin subjected to artificial aging. Four bisacrylic resins were evaluated, namely, control, chitosan-modified material, nanodiamond-modified material, and chitosan–nanodiamond-modified material. Tw
Braz. oral res.. Publicado em: 04/04/2019
-
9. Surface Topography, Gloss and Flexural Strength of Pressable Ceramic After Finishing-Polishing Protocols
Resumo O objetivo deste estudo foi avaliar o efeito de diferentes protocolos de acabamento e polimento na rugosidade da superfície, brilho, resistência à flexão biaxial e morfologia de cerâmica prensada. Trinta discos de cerâmica (12x1 mm) foram produzidos e divididos em cinco grupos (n=6): CT- controle (glaze); DA- ponta diamantada de granulação fin
Braz. Dent. J.. Publicado em: 04/04/2019
-
10. Síntese da perovskita [KNbO3]0,9[BaNi0,5Nb0,5O3-δ]0,1 por combustão em solução
Resumo O desenvolvimento de perovskitas ferroelétricas capazes de absorver a luz visível, particularmente KBNNO - [KNbO3]0,9[BaNi0,5Nb0,5O3-δ]0,1 (band-gap Eg= 1,39 eV), tem encorajado a aplicação desses materiais na camada ativa de células solares. Em dispositivos fotovoltaicos, esses materiais podem permitir a obtenção de voltagens superiores à ma
Cerâmica. Publicado em: 2019-01
-
11. Use of Infrared Spectroscopy and Near Infrared Hyperspectral Images to Evaluate Effects of Different Chemical Agents on PET Bottle Surface
PET - poly (ethylene terephthalate) - bottle surfaces were exposed to chemical agents and evaluated with middle infrared spectroscopy (MIR) and near infrared hyperspectral imaging (HSI-NIR). Images (928-2.524 nm) were acquired at different times from bottle surfaces exposed to alkaline, acidic and ethanolic media. Savitzky-Golay smoothing (2nd order polynomi
Mat. Res.. Publicado em: 09/08/2018
-
12. Membranas Compuestas: propiedades superficiales y estabilidad térmica
ABSTRACT The composite membranes were manufactured with crosslinking poly(vinyl alcohol) on polyethersulfone porous membranes by coating process. PES membranes were exposed to air plasma for the purpose of surface modification. The coating of the support membrane was carried out by using a polymer matrix with a crosslinking agent. The physico-chemical proper
Matéria (Rio J.). Publicado em: 19/07/2018