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Mostrando 13-24 de 2690 artigos, teses e dissertações.
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13. Structure-Physical Properties Relationship of Eutectic Solvents Prepared from Benzyltriethylammonium Chloride and Carboxylic Acids
Deep eutectic solvents (DESs) have attracted the attention of the researchers as alternative solvents due to desirable properties such as easy preparation and high thermal stability. In this work, it was reported the preparation of five DESs from benzyltriethylammonium chloride (BTEAC) as quaternary ammonium salt (QAS) and carboxylic acids (oxalic, malonic o
J. Braz. Chem. Soc.. Publicado em: 2021-03
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14. THEORETICAL INVESTIGATIONS ON DETONATION PERFORMANCE AND STABILITY OF THE DIFLUOROAMINO-PRISMANE DERIVATIVES
The difluoroamino derivatives of prismane were designed and calculated at the B3LYP/6-311G** level. The detonation performances, as well as the band gap, were investigated to look for high energy density compounds. Our calculations showed that difluoroamino group is an effective substitute group for increasing density and heats of formation. All compounds ha
Quím. Nova. Publicado em: 2021-02
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15. Properties of Cu-Co Composite Catalysts for Synthesis of Aliphatic Alcohols
Cu-Co-containing cellulose-based carbon composite materials (Cu-Co/Cel) were formed by a matrix isolation method. Using X-ray diffraction (XRD), transmission electron microscopy (TEM), infrared-Fourier spectroscopy (IR-Fourier spectroscopy), and non-isothermal research methods, the physicochemical properties of the composites were established. The catalysts
J. Braz. Chem. Soc.. Publicado em: 2021-02
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16. An Alternative Description for the Electronegativity Difference in Binary Ionic Solids
We are introducing an alternative analytical expression to the electronegativity difference (∆χ) as a function of the charge ge, g is the charge factor, the fraction of the electronic charge devoted to the bond and e the elementary charge, the packing factor (p) and the effective atomic number (Zeff) of binary ionic solids, by using the very basic Coulomb
J. Braz. Chem. Soc.. Publicado em: 2021-02
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17. COMPARAÇÃO ENTRE MÉTODOS PARA DETERMINAÇÃO DE CARGAS ATÔMICAS EM SISTEMAS MOLECULARES: A MOLÉCULA N-{N-(PTERINA-7-IL)CARBONILGLICIL}-L-TIROSINA (NNPT)
Selecting a method to compute partial atomic charges is not trivial because different methods usually provide different charge values and there is no consensus on the most useful approach. In this work, Mulliken, MBS, Chelp, Chelpg, MK, Hirshfeld, NPA, DMA and AIM methods were selected to compute atomic charges and electric dipole moment vector of N-{N-(Pter
Quím. Nova. Publicado em: 2021-02
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18. Agradecimentos aos Pareceristas ad hoc do volume 18 (ano 2020)
According to the World Health Organization (WHO), Chagas disease (CD), whose etiological agent is the Trypanosoma cruzi (T. cruzi) parasite, affects about eight million people, mainly in Latin America. The cruzain enzyme is highlighted among the main biological targets, since it is the most abundant of the cysteine protease class from T. cruzi and is involve
Trab. educ. saúde. Publicado em: 2021-01
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19. Molecular Modelling Study of Heteroarylamide/Sulfonamide Compounds with Antitrypanosomal Activity
According to the World Health Organization (WHO), Chagas disease (CD), whose etiological agent is the Trypanosoma cruzi (T. cruzi) parasite, affects about eight million people, mainly in Latin America. The cruzain enzyme is highlighted among the main biological targets, since it is the most abundant of the cysteine protease class from T. cruzi and is involve
J. Braz. Chem. Soc.. Publicado em: 2021-01
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20. POLÍMERO DE IMPRESSÃO MOLECULAR PARA O TIACLOPRIDO: UMA INVESTIGAÇÃO TEÓRICA
Thiacloprid (TCP) is a synthetic insecticide, belonging to the class of neonicotinoids (NNCs), which present potential damages to the environment, biodiversity and human health, being necessary its constant monitoring. In this sense, molecularly imprinted polymers (MIPs) have been shown as an excellent alternative for the separation science, since they can r
Quím. Nova. Publicado em: 2020-12
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21. Calcium oxalate content from two Amazonian amilaceous roots and the functional properties of their isolated starches
Abstract The calcium oxalate content from two Amazonian amilaceous roots, Xanthosoma sagittifolium and Pachyrhizus tuberosus, before and after cooking were studied in the present work. Calcium oxalate raphides were observed by light microscopy in longitudinal sections from fresh tubers. The functional properties and physicochemical characteristics of isolate
Food Sci. Technol. Publicado em: 2020-09
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22. APRESENTAÇÃO - História Antiga: Diferentes Perspectivas
Biodiesel is a suitable alternative to replace the petro-diesel. The biodiesel is formed by unsaturated esters easily degraded by interferences of oxygen, temperature, contact with metals or contaminants. The aim of this research was to investigate the biodiesel degradation process via 1H nuclear magnetic resonance (NMR) spectroscopy, observing the olefinic,
Rev. Bras. Hist.. Publicado em: 2020-08
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23. Evaluation of the Oxidation Degradation Process of Biodiesel via 1H NMR Spectroscopy
Biodiesel is a suitable alternative to replace the petro-diesel. The biodiesel is formed by unsaturated esters easily degraded by interferences of oxygen, temperature, contact with metals or contaminants. The aim of this research was to investigate the biodiesel degradation process via 1H nuclear magnetic resonance (NMR) spectroscopy, observing the olefinic,
J. Braz. Chem. Soc.. Publicado em: 2020-08
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24. A UNIFIED FORMULA FOR HYDROCARBONS WITH APPLICATIONS TO FUNCTIONAL GROUPS
Was supposed a numerical relationship between atoms of Hydrogen and Carbon in a hydrocarbon, assumption valid for all types of chains. In the proposed equation, variables such as number and types of carbon bonds are present, as well as the possible cycles. It was shown that the equation reduces to the known “general formulas” when applied to the type of
Quím. Nova. Publicado em: 20/07/2020