Spectroscopy Analysis
Mostrando 1-12 de 1837 artigos, teses e dissertações.
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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
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2. Study of nanocomposites with carbon nanotubes and their tendency for carbon organization
Abstract The carbon derived from the thermal treatment of modified phenolic resins (PR) tends to organize into graphitic lamellae or turbostratic carbon and is commonly considered non-graphitizable. In this study, nanocomposites were synthesized with modified phenolic resin (Novolac) used as the matrix and oxidized multi-walled carbon nanotubes (NTox) in amo
Cerâmica. Publicado em: 2022
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3. Light-Assisted Batch Injection Analysis of Glucose Exploiting a p-n-Homojunction Based on Cu2O
This work describes the development of a photoelectrochemical sensor for glucose quantification exploiting a light assisted-batch injection analysis (BIA) cell. A light-emitting diode (LED) lamp was employed to control the incidence of light on the p-Cu2O/n-Cu2O/fluorine-doped tin oxide (FTO) photoactive platform in BIA cell. The p-Cu2O/n-Cu2O/FTO platform w
Journal of the Brazilian Chemical Society. Publicado em: 2022
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4. Preparation and performance of magnetic zirconium-iron oxide nanoparticles loaded on palygorskite in the adsorption of phosphate from water
Magnetic zirconium-iron oxide nanoparticles loaded on palygorskite as a low-cost adsorbent was produced by one-step co precipitation technique and its properties for phosphate adsorption were overall investigated. The Brunauer Emmett Teller (BET) specific surface area analysis, scanning electron microscopy (SEM), thermo gravimetric analysis (TGA), Fourier tr
Química Nova. Publicado em: 2022
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5. Thermostimulated crystal structure transformation of the polymineral clay submicron particles
Abstract Changes in the structure of phyllosilicate microparticles of submicron fractions of polymineral clay with an average size of 290 nm, as well as changes in the positions of impurity ions of transition metals in the crystal lattice, were studied by X-ray diffraction analysis, Fourier transform infrared spectroscopy, and high-resolution electron parama
Cerâmica. Publicado em: 2022
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6. VIBRATION CHARACTERISTICS, CHEMICAL BONDS AND WEAK INTERACTIONS OF 4- AND 5-HYDROXYSALICYLIC ACID INVESTIGATED BY TERAHERTZ SPECTROSCOPY AND DENSITY FUNCTIONAL THEORY
The terahertz (THz) absorption spectra of 4- and 5-hydroxysalicylic acid were measured by terahertz time-domain spectroscopy (THz-TDS) in the range of 0.4-2.8 THz. The unit cells of both were calculated by density functional theory (DFT), and the theoretical simulation and experimental data were basically in agreement. To further interpret the origin of the
Química Nova. Publicado em: 2022
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7. Catalytic Effects of Ruthenocene Bimetallic Compounds Derived from Fused Aromatic Ring Ligands on the Main Oxidizing Agent for Solid Rocket Motor
We report the catalytic effect of three ruthenocene bimetallic compounds derived from fused aromatic rings of general formula [{Cp*Ru}2L], with Cp*: pentamethylcyclopentadiene and L = pentalene (1), 2,6-diethyl-4,8-dimethyl-s-indacene (2), and 2,7-diethyl-as-indacene (3), on the thermal decomposition of ammonium perchlorate (AP). The new compound 3 was chara
Journal of the Brazilian Chemical Society. Publicado em: 2022
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8. Assessment of Urban Contamination by Sewage in Sediments from Ipojuca River in Caruaru City, Pernambuco, Brazil
The Ipojuca River is considered the third most polluted river in Brazil due to the intense anthropogenic activities in the surrounding urban areas. The most important effluent is sewage discharge, which is responsible for considerable contamination. Traditional analyses (infrared spectroscopy, organic matter (OM), elemental analysis and granulometry) and adv
Journal of the Brazilian Chemical Society. Publicado em: 2022
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9. Multimodal Neuromonitoring During Pediatric Cardiac Surgery
Abstract Introduction: Neuromonitoring (electroencephalogram [EEG] and cerebral oximetry) is essential for appropriate anesthesia and neuroprotection assessment during pediatric cardiac surgery. Methods: We describe the intraoperative pediatric multimodal and multiparametric neuromonitoring pattern of the software system Neuron-Spectrum (Kandel®) that con
Brazilian Journal of Cardiovascular Surgery. Publicado em: 2022
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10. Rapid Recognizing the Producing Area of a Tobacco Leaf Using Near-Infrared Technology and a Multi-Layer Extreme Learning Machine Algorithm
A novel recognition method was put forward to identify the producing areas of the flue-cured tobacco leaves rapidly and non-destructively by using a near-infrared (NIR) spectrometer and a multi-layer-extreme learning machine (ML-ELM) algorithm. In contrast to traditional linear discriminant analysis (LDA) and extreme learning machine (ELM) algorithms, the ac
Journal of the Brazilian Chemical Society. Publicado em: 2022
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11. Per-Aqueous Liquid Chromatography for the Separation of Polar Compounds Preparation and Characterization of Poly(ethylene oxide co dimethylsiloxane) Based Stationary Phase
Poly(ethylene oxide-co-dimethylsiloxane) was thermally immobilized on silica particles-Si(PEO)-to separate small polar compounds with water-rich mobile phases. Poly(ethylene oxide-co-dimethylsiloxane) content on Si(PEO) stationary phase was optimized using a central composite design. Infrared spectroscopy, scanning electron microscopy, and thermogravimetric
Journal of the Brazilian Chemical Society. Publicado em: 2022
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12. Biogenic synthesis of silver nanoparticles from thyme extract for functionalization of a bioactive glass produced from rice husk ash
Abstract The rice husk, agro-industrial residue, stands out for having silica, the main oxide former of the bioactive glass. To avoid contamination in this biomaterial, substances with bactericidal properties, like silver can be incorporated. Thus, the objective of this work is the synthesis of silver nanoparticles to functionalize a bioactive glass synthesi
Cerâmica. Publicado em: 2022