Diffuse Reflectance
Mostrando 25-36 de 114 artigos, teses e dissertações.
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25. ZNO and AG-ZNO crystals: synthesis, characterization, and application in heterogeneous photocatalysis
ZnO and Ag-ZnO were synthesized in a simple and efficient manner by thermal decomposition of zinc oxalate and silver/zinc mixed oxalate. The influence of the addition of metallic silver on ZnO particles and the effect of temperature in the thermal treatment were investigated. The samples were characterized by thermogravimetric analysis, Raman, X-ray diffract
Quím. Nova. Publicado em: 2016-05
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26. Novel Ag3PO4/CeO2 p-n Hierarchical Heterojunction with Enhanced Photocatalytic Performance
The composite Ag3PO4/CeO2 photocatlyst, a novel p-n type heterojunction, has been successfully fabricated through a facile hydrothermal process combined with a successive in situ precipitation technique. The X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM) and UV-visible diffuse reflectance
Mat. Res.. Publicado em: 26/04/2016
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27. Potential of Spectroradiometry to Classify Soil Clay Content
ABSTRACT Diffuse reflectance spectroscopy (DRS) is a fast and cheap alternative for soil clay, but needs further investigation to assess the scope of application. The purpose of the study was to develop a linear regression model to predict clay content from DRS data, to classify the soils into three textural classes, similar to those defined by a regulation
Rev. Bras. Ciênc. Solo. Publicado em: 26/04/2016
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28. Comparison of Gold CD-R Types as Electrochemical Device and as Platform for Biosensors
The construction of gold electrodes using 3 kinds of gold recordable compact discs (CDtrodes) and characterization by electrochemical and spectroscopic techniques are herein reported. Following a surface pretreatment in 0.5 mol L-1 sulfuric acid (H2SO4), the electrochemical experiments were performed in the presence of redox couple ferro/ferricyanide [Fe(CN)
J. Braz. Chem. Soc.. Publicado em: 2016-04
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29. Green method by diffuse reflectance infrared spectroscopy and spectral region selection for the quantification of sulphamethoxazole and trimethoprim in pharmaceutical formulations
Um método alternativo para quantificação de sulfametoxazol (SMZ) e trimetoprima (TMP), empre gando espectrometria por refletância difusa no infra vermelho por transformada de Fourier (DRIFTS) e regressão por mínimos quadrados parciais (PLS) foi desenvolvido. Regressão por mínimos quadrados parciais por intervalo (iPLS) e por sinergismo de intervalos
An. Acad. Bras. Ciênc.. Publicado em: 04/03/2016
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30. Use of Natural Rubber Membranes as Support for Powder TiO2and Ag/TiO2 Photocatalysts
The purpose of this study was to synthesize TiO2-polymer composites able to act as photocatalyst membranes. TiO2 catalysts were prepared using the sol-gel method to contain 0.0, 0.5, 1.0, and 2.0 wt.% of embedded Ag particles, subsequently incorporated into natural rubber latex at a weight fraction of 15%. Samples of these ceramic powders were suspended in a
J. Braz. Chem. Soc.. Publicado em: 2016-03
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31. Synthesis and Characterization of Mesoporous Nb2O5 and Its Application for Photocatalytic Degradation of the Herbicide Methylviologen
This article reports the characterization of mesoporous Nb2O5 synthesized by the sol-gel method for application in photocatalysis. The emerging contaminant methylviologen was employed for photocatalytic tests. Parameters inherent to the synthesis process, such as stirring rate, aging temperature, and calcination temperature, were employed for a range of valu
J. Braz. Chem. Soc.. Publicado em: 2016-02
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32. Effect of the Fuels Glycine, Urea and Citric Acid on Synthesis of the Ceramic Pigment ZnCr2O4 by Solution Combustion
AbstractIn this study, ceramic nanopigment ZnCr2O4was prepared by solution combustion using glycine, urea and citric acid as fuels. The objective is to study the influence of fuel on the morphology and the diffuse reflectance spectrum. The nanoparticles were characterized by field emission scanning electron microscopy (FESEM), the phase was investigated by X
Mat. Res.. Publicado em: 2015-10
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33. Rapid Determination of Lead in Progressive Hair Dye Lotion by Spot Test/Diffuse Reflectance Spectroscopy with a Paper Platform
A simple, inexpensive, and clean methodology employing a combined spot test/diffuse reflectance spectroscopy procedure was developed and applied for the quality control analysis of lead in hair dyes, using a filter paper platform. The method is based on the complexation reaction of lead, present in a pH 2.8 buffer medium containing tartaric acid and sodium a
J. Braz. Chem. Soc.. Publicado em: 2015-10
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34. Optical absorption enhancement in sensitized ZnO nanorods for solar cells
ABSTRACTThe Optical Properties of ZnO Nanorods (NR) sensitized with different semiconductors in Core-Shell nanostructures were studied, comparing them with those of bare ZnO NR. Experimental measurements of Transmittance and Diffuse Reflectance show an increased light absorption at the solar spectrum and the appearances of new absorption edges (AE). The meas
Matéria (Rio J.). Publicado em: 2015-09
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35. Layered Zinc Hydroxide Salts Intercalated with Anionic Surfactants and Adsolubilized with UV Absorbing Organic Molecules
Two anionic surfactants, dodecylsulfate (DDS) and dodecylbenzenesulfonate (DBS), were intercalated into layered zinc hydroxide salts (LHS) using the direct alkaline co-precipitation method, and characterized by powder X-ray diffraction (PXRD), Fourier-transform infrared (FTIR) and thermogravimetric analysis/differential thermal analysis (TGA/DTA). Different
J. Braz. Chem. Soc.. Publicado em: 2015-09
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36. Nitrogen dopedTiO2photoactive in visible light
abstractIn this research TiO2 modified with nitrogen has been prepared. The synthesis method used was sol gel from the hydrolysis of titanium tetrabutoxide with urea solution, combined with a low temperature treatment at atmospheric pressure. The theoretical mole ratio N/Ti was equal to 0.5 and the theoretical mole ratio HNO3/TiO2 was equal to 0.5. The solid
Matéria (Rio J.). Publicado em: 2015-09