Spectroscopy
Mostrando 13-24 de 6190 artigos, teses e dissertações.
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13. 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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14. 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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15. 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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16. 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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17. Production of nanostructured crystalline composite using residual ashes from flocculated sludge burning process in a poultry slaughterhouse wastewater treatment system
Abstract Nanostructured crystalline composite (activated carbon) was synthesized from residual ashes of the burning process of the sludge generated in the flotation step of a poultry slaughterhouse and was used for Allura red dye adsorption. The ashes were chemically activated using two types of reagents, H2O2 and H3PO4, and the structure, morphology, and su
Cerâmica. Publicado em: 2022
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18. 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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19. Enhanced Catalytic Performance of Strontium-Doped Lanthanum Manganites by the Presence of Molybdenum Oxides for Electro-Reduction of Hydrogen Peroxide
In this work, two catalysts, lanthanum manganite strontium-doped perovskite without (LSM) and with (LSMMO) mixed molybdenum oxides, were synthesized by the sol-gel route and deposited by immersion in carbon cloth substrates. Their performance as cathodes in the hydrogen peroxide reduction reaction (HPRR) and oxygen reduction reaction (ORR) was investigated t
Journal of the Brazilian Chemical Society. Publicado em: 2022
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20. Effect of sintering temperature on mechanical and bioactivity properties of bioactive glass and cordierite composite
Abstract In this study, a composite of bioactive glass (BG) and cordierite (BG-cord) was proposed to increase the strength and bioactivity of BG. Both BG and cordierite were separately synthesized with the method of glass melting, then, they were used to fabricate BG-cord with a variation of sintering temperature (600 to 1000 °C). The highest diametral tens
Cerâmica. Publicado em: 2022
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21. Synthesis of Conjugated Molecules Based on Dithienopyrrole Derivatives and Pyrene as Chemosensor for Mesotrione Detection
The conjugated molecules based on pyrene and dithienopyrrole derivatives including 4-(2-ethylhexyl)-2-(pyren-1-yl)-4H-dithieno[3,2-b:2’,3’-d]pyrrole (EP4HP) and 4-(2-ethylhexyl)-2,6-di(pyren-1-yl)-4H-dithieno[3,2-b:2’,3’-d]pyrrole (EDP4HP) have been successfully synthesized via C-H direct arylation reaction. The structures of these conjugated molecul
Journal of the Brazilian Chemical Society. Publicado em: 2022
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22. Phase transformation of kaolinite to hexagonal kalsilite using K2CO3
Abstract Hydrothermal synthesis of kalsilite was facilitated by the inclusion of potassium carbonate (K2CO3) as the source of the potassium ion. After a 24 h reaction at 220 °C, kaolin clay treated with 1.25 M K2CO3 showed the most significant peaks at 2θ of 28.5° and 34.7° by X-ray diffraction corresponding to the hexagonal kalsilite. In addition, field
Cerâmica. Publicado em: 2022
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23. 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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24. 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