Spectroscopic Analysis
Mostrando 13-24 de 390 artigos, teses e dissertações.
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13. 3-Aminofurostane Alkaloids from Solanum paniculatum (“Jurubeba Verdadeira”) Roots
The roots of Solanum paniculatum (Solanaceae) have extensively been used in folk medicine to treat liver infections and as a diuretic. Ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS/MS) were used for the profiling and structural characterization of alkaloids from the roots of S. paniculatum. Six
J. Braz. Chem. Soc.. Publicado em: 2020-05
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14. JUDD-OFELT ANALYSIS OF Tb3+ AND UPCONVERSION STUDY IN Yb3+-Tb3+ CO-DOPED CALIBO GLASSES
We report on the study of the spectroscopic properties in Ytterbium-Terbium (Yb3+-Tb3+) co-doped calcium lithium borate (CaLiBO) glasses, with the study’s focus being on the upconversion process. Intensity parameters Ωλ for CaLiBO:Tb3+ are determined by the Judd-Ofelt method to be Ω2 = 15.5 × 10-20 cm2, Ω4 = 1.90 × 10-20 cm2 and Ω6 = 3.69 × 10-20 c
Quím. Nova. Publicado em: 2020-02
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15. ESQUARAÍNAS CIS E TRANS SUBSTITUÍDAS: APLICAÇÃO EXPERIMENTAL DA TEORIA DE GRUPO EM ESPECTROSCOPIA VIBRACIONAL
This work shows a practical application of the group theory to a relatively simple molecular system, as well its impact in the results obtained through vibrational spectroscopic techniques. Squaraines substituted by dicyanemethylene groups have been extensively studied, and after minor approaches in the sense to facilitate the point group determination, they
Quím. Nova. Publicado em: 05/12/2019
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16. SPECTROSCOPIC CHARACTERIZATION OF PEDOT:PSS CONDUCTING POLYMER BY RESONANCE RAMAN AND SERRS SPECTROSCOPIES
Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) synthesis was monitored by resonance Raman (RR) and surface-enhanced resonance Raman scattering (SERRS) spectroscopies and both the oxidation of the polymer and the effects of chain length were assessed by vibrational analysis. It was supported by theoretical models of oligomers, with charge
Quím. Nova. Publicado em: 05/12/2019
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17. Microwave radiation influence on the thermal and spectroscopic properties of Na-birnessite-type material
Resumo No presente trabalho, apresenta-se um estudo da influência da radiação micro-ondas nas propriedades térmica e espectroscópica, assim como estrutural (ordem-desordem) e morfológica, de óxido de Mn estruturado em camada tipo Na-birnessita. A rota empregada para obtenção da matriz lamelar foi a precipitação redox. Os produtos foram caracteriza
Cerâmica. Publicado em: 14/11/2019
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18. Identification of compounds from chufa (Eleocharis dulcis) peels with inhibitory acrylamide formation activity
Abstract Five compounds were isolated from the peels of chufa (Eleocharis dulcis (Burm.f.) Trin. ex Hensch., Cyperaceae). The chemical structures were determined by various spectroscopic analysis methods, including 1D and 2D NMR, and by comparison with literature data. All compounds were isolated for the first time from the peels of chufa. Compounds orcinol
Rev. bras. farmacogn.. Publicado em: 17/10/2019
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19. Study of the metallurgical bond between 316 steel substrates and NiCrAlY coating sprayed by HVOF and irradiated with a low power CO2 laser
RESUMO Considerando a importância do desenvolvimento de novos materiais ao longo dos últimos anos; os pesquisadores vêm estudando soluções eficazes através do uso de revestimentos de alta dureza para aplicação em ferramentas de corte e matrizes de conformação. Revestimentos de carboneto de tungstênio (WC) são um dos mais utilizados em sistemas de
Matéria (Rio J.). Publicado em: 16/09/2019
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20. Evaluation of quality parameters and chromatographic, spectroscopic, and thermogravimetric profile of Patauá oil (Oenocarpus bataua)
Abstract The objective of this research was to evaluate the quality parameters and the chromatographic, thermogravimetric, and spectroscopic profile of Patauá oil (Oenocarpus bataua). All analyses were performed according to the Recommended Practices of the American Oil Chemists’ Society (AOCS). The parameters obtained indicate conservation quality standa
Food Sci. Technol. Publicado em: 09/09/2019
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21. Influence of Particles Size on NIR Spectroscopic Estimations of Charcoal Properties
ABSTRACT The objective of this study was to evaluate the influence of particle size of charcoal samples on the predictive model statistics of charcoal chemical composition based on the NIR spectroscopy. Spectra of Acacia and of Eucalyptus charcoal were collected in the 100, 60 and 40 mesh granulometry, besides the powder remaining at the bottom of the sieves
Floresta Ambient.. Publicado em: 09/09/2019
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22. Caryopristimerin, the First Example of a Sesquiterpene-Triterpene Homo Diels-Alder Adduct, and a New 29-nor-Friedelane from Roots of Salacia crassifolia
Two new compounds, caryopristimerin and 2α,3α,22β-trihydroxy-21-oxo-29-nor-friedelan-24-oic acid, were isolated from the hexane/ethyl ether extract of Salacia crassifolia roots. Caryopristimerin represents the first example of a homo Diels-Alder adduct of a sesquiterpene and a triterpene, and the new 29-nor-friedelane displays a highly oxygenated A ring w
J. Braz. Chem. Soc.. Publicado em: 04/07/2019
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23. Dielectric and Raman spectroscopy studies of (Na0.5Bi0.5)TiO3 lead-free ceramic
Resumo Neste estudo, amostras de titanato de bismuto e sódio (Na0,5Bi0,5)TiO3 (NBT) foram preparadas usando a técnica de estado sólido. A sinterização foi feita a 1200 ºC por 4 h ao ar. A análise de difração de raios X realizada à temperatura ambiente mostrou a formação de um composto de fase única com um sistema cristalino romboédrico. Caracte
Cerâmica. Publicado em: 06/06/2019
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24. Gliclazide reduced oxidative stress, inflammation, and bone loss in an experimental periodontal disease model
Abstract Objective The aim of this study was to evaluate the effects of gliclazide on oxidative stress, inflammation, and bone loss in an experimental periodontal disease model. Material and Methods Male albino Wistar rats were divided into no ligature, ligature, and ligature with 1, 5, and 10 mg/kg gliclazide groups. Maxillae were fixed and scanned usin
J. Appl. Oral Sci.. Publicado em: 21/02/2019