Spectral Properties
Mostrando 1-12 de 414 artigos, teses e dissertações.
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1. Impact of fuel quantity on luminescence properties of Sr3Al2O6:Eu by combustion synthesis
Abstract The photoluminescent behavior of Eu-doped Sr3Al2O6 obtained by highly efficient solution combustion synthesis is reported. In order to understand the influence of the fuel on the synthesis, the stoichiometric quantity and an excess of fuel were evaluated. By adjusting the amount of fuel, different luminescence responses were obtained, allowing europ
Cerâmica. Publicado em: 2023
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2. DESENVOLVIMENTO DE ACESSÓRIO PORTÁTIL DE CONTROLE DE TEMPERATURA PARA MEDIDAS ESPECTROSCÓPICAS
Temperature is a natural phenomenon that may modify the structure of chemical compounds and hence their properties. We aimed to develop a simple portable system based on the Peltier principle for spectral characterization of compounds with temperature-dependent structure. The device was constructed and adapted to three pieces of equipment: X-ray diffractomet
Química Nova. Publicado em: 2022
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3. Characterization and mechanical properties of one-part geopolymer based on a pure metakaolin
Abstract Geopolymers are amorphous silicate polymers that have been extensively studied due to their applications, scientific and technical relevance, and their potential as cement in substitution to Portland. Much of the focus has been in the use of precursors and aggregates that are rarely pure and homogeneous with the use of tailings being very common. Th
REM - International Engineering Journal. Publicado em: 2022
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4. Evaluation of the Metabolic Profile of Arabica Coffee via NMR in Relation to the Time and Temperature of the Roasting Procedure
Coffee is one of the most popular and consumed products in the world, with high nutritional value and economic importance. However, some factors can change the organoleptic properties of a coffee species, without causing significant damage such as loss of important components. The present study evaluated the chemical profile, via nuclear magnetic resonance (
J. Braz. Chem. Soc.. Publicado em: 2021-01
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5. AUTENTICAÇÃO DE ORÉGANO (Origanum vulgare L.) ORGÂNICO UTILIZANDO ESPECTROSCOPIA NIR E QUIMIOMETRIA
In recent years, the consumption of organic foods has considerably increased. The basic difference between organic and non-organic food products is the way in which they are produced and processed, and the authenticity of these products is a current trend in food science and analytical chemistry. In this sense, the objective of this work was to propose an an
Quím. Nova. Publicado em: 2020-12
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6. MÉTODO MANUAL PARA DEPOSIÇÃO DE TINTAS FOTOLUMINESCENTES BASEADAS EM LOFS MISTAS APLICADO A CODIFICAÇÃO DE DOCUMENTOS
In this work, the process of synthesis of Metal-Organic Frameworks containing lanthanide ions (LOFs), accelerated via a precipitating agent, capable of accelerating the process of nucleation of MOF crystals, in order to explore the optical properties of this precursor solution (SP_Gd/EU-MOF), as a quick-response photoluminescent material in the coding of off
Quím. Nova. Publicado em: 2020-12
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7. Sunlight-Driven Dehydrogenative Oxidation Photocatalysis by a Mononuclear Complex Acting as both Chromophore and Catalyst
Under simulated solar irradiation in the visible spectral region, the catalytically active RuIV-oxo species [Ru(O)(bpy)(tppz)]2+ (tppz = tetrapyridylpyrazine, a strongly π-accepting tridentate N, N, N-ligand) is produced directly from a single metal-to-ligand charge-transfer (MLCT) photoexcitation of the resting RuII-aquo complex [Ru(H2O)(bpy)(tppz)]2+ in a
J. Braz. Chem. Soc.. Publicado em: 2020-11
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8. A Regional Legacy Soil Dataset for Prediction of Sand and Clay Content with Vis-Nir-Swir, in Southern Brazil
ABSTRACT The success of soil prediction by VIS-NIR-SWIR spectroscopy has led to considerable investment in large soil spectral libraries. The aims of this study were 1) to develop a soil VIS-NIR-SWIR spectroscopy approach using legacy soil samples to improve spectral soil information in a regional scale; (2) to compare six spectral preprocessing techniques;
Rev. Bras. Ciênc. Solo. Publicado em: 15/08/2019
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9. AlradSpectra: a Quantification Tool for Soil Properties Using Spectroscopic Data in R
ABSTRACT Soil reflectance spectroscopy has become an innovative method for soil property quantification supplying data for studies in soil fertility, soil classification, digital soil mapping, while reducing laboratory time and applying a clean technology. This paper describes the implementation of a Graphical User Interface (GUI) using R named AlradSpectra.
Rev. Bras. Ciênc. Solo. Publicado em: 29/07/2019
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10. Ligand and Solvent Effects on the Structural and Optical Properties of Au13L83+ Clusters: a Density Functional Theory Study
Density functional theory (DFT) calculations have been performed to develop a systematic structural analysis of Au13L83+, where L = SCH3, SeCH3, SCH2OCH3 and S(CH2)2NH2, in order to examine the influence of different ligands. Binding energy calculations indicate that the gold core is more stabilized by the ligand in the following sequence S(CH2)2NH2 > SCH2OC
J. Braz. Chem. Soc.. Publicado em: 04/07/2019
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11. Heritability of advertisement call properties of the Japanese quail
Resumo O objetivo deste estudo foi investigar as variâncias e covariâncias genéticas entre as características do canto de anúncio de codornas japonesas. A duração da primeira, segunda e terceira sílaba, o comprimento do intervalo 1 (entre a primeira e a segunda sílaba), o intervalo 2 (entre a segunda e a terceira sílaba) e o amortecimento (extensã
Braz. J. Biol.. Publicado em: 30/05/2019
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12. Space-Temporal analysis of suspended sediment in low concentration reservoir by remote sensing
RESUMO O estudo de pequenos reservatórios e com baixa concentração de sedimentos em suspensão (CSS) ainda é um desafio para o sensoriamento remoto. Neste trabalho estimamos a CSS a partir das propriedades óticas da água e de imagens orbitais. Realizamos campanhas em datas escolhidas em função do calendário de passagem dos sensores, sazonalidade das
RBRH. Publicado em: 02/05/2019