Theoretical Experimental Study
Mostrando 1-12 de 512 artigos, teses e dissertações.
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1. Synthesis and Molecular Modeling Study of Two Bromo-Dimethoxybenzaldehydes
This work describes the synthesis, molecular structure, and packaging of the compounds 6-bromo-2,3-dimethoxybenzaldehyde (6-BRB) and 5-bromo-2,3-dimethoxybenzaldehyde (5 BRB). Characterization in the solid-state was carried out by X-ray diffraction, and the analysis of the interactions was described by the Hirshfeld surface, which helps in understanding the
Journal of the Brazilian Chemical Society. Publicado em: 2022
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2. 2-(Pyridin-4yl)benzothiazole and Its Benzimidazole-Analogue: Biophysical and in silico Studies on Their Interaction with Urease and in vitro Anti-Helicobacter pylori Activities
In this study, the interaction between benzothiazole (BTA, concentration of a drug required for 50% inhibition in vitro (IC50) = 0.77 mM) and benzimidazole (BIA, IC50 = 2.14 mM) with urease was quantitatively assessed, using UV-Vis, molecular fluorescence, and circular dichroism. The results showed that both compounds interact with urease by a static fluores
Journal of the Brazilian Chemical Society. Publicado em: 2022
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3. CURCUMINA COMO INDICADOR NATURAL DE PH: UMA ABORDAGEM TEÓRICA-EXPERIMENTAL PARA O ENSINO DE QUÍMICA
This paper proposes the development of a simple experiment with easily accessible and low cost materials, enabling its practice with or without laboratory infrastructure, with feasibility for computational theoretical study. On the other hand, the objective of the work is to develop a chemical experiment that demonstrates that the chromophore curcumin (natur
Quím. Nova. Publicado em: 2021-02
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4. INSIGHT INTO THE CONFORMATIONAL SPACE OF N-BENZYL-N-(FURAN-2-YLMETHYL)ACETAMIDE BY NMR SPECTROSCOPY AND DFT CALCULATIONS
In this study, the conformational behavior of N-benzyl-N-(furan-2-ylmethyl) acetamide in chloroform was addressed by using a combined experimental/theoretical strategy using NMR spectroscopy and quantum chemical calculations. The 1H and 13C one-dimensional NMR spectra, as well as the two-dimensional HSQC-DEPT and HMBC-DEPT NMR spectra, evinced the presence o
Quím. Nova. Publicado em: 2021-01
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5. INFLUÊNCIA DA FORÇA IÔNICA NA ESTIMATIVA DE pKa POR MÉTODO VOLTAMÉTRICO
The voltammetry is an important analytical technique and also useful for pKa determination. It is a usual procedure of this technique to employ inert electrolyte concentration 100 times higher than redox compound concentration further a pH buffer. However, the ionic strength changes with the solution pH. In this work, we study the consequences of this proced
Quím. Nova. Publicado em: 2020-12
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6. THEORETICAL ANALYSIS AND EXPERIMENTAL STUDY ON THE PROCESS OF CONVEYING AGRICULTURAL FIBER MATERIALS BY SCREW CONVEYORS
ABSTRACT To improve the conveying efficiency and working stability of a screw conveyor, the feeding methods, running conditions and flow characteristics of materials were studied by theoretical analysis and experiments. The theoretical analysis results show that the screw conveyor runs more stably when the helix angle of the screw blade is equal to the movin
Eng. Agríc.. Publicado em: 2020-10
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7. LEARNING ABOUT EDGE EFFECTS AND ULTRAMICROELECTRODES IN ELECTROCHEMISTRY: SYNERGY BETWEEN EXPERIMENTS AND SIMULATIONS
A short experimental activity aimed at upper level undergraduate students or beginner researchers is presented to introduce the concepts of edge effects and hemispherical diffusion at ultramicroelectrodes. Students will perform simple cyclic voltammetry experiments varying the scan rate and using disk electrodes with different radii. They are then asked to i
Quím. Nova. Publicado em: 2020-09
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8. Effects of addition of engineered ZnO nanoparticles on the stability of colloidal suspensions containing TiO2 interacting with sandy soil
Abstract The stability of colloidal suspensions of engineered nanoparticles in the environment is of great interest for the risk assessment and treatment of hazardous materials. The relevance of this study is due to the evidence that engineered nanoparticles have been produced and used in commercial products in large scale, especially ZnO and TiO2, which are
REM, Int. Eng. J.. Publicado em: 2020-06
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9. Crystal Structure and 1H NMR Experimental and Theoretical Study of Conformers of 5-Methyl-1-(4’-methylphenylsulfonylamino)-1H-[1,2,3]-triazole-4-carboxylic Acid Ethyl Ester and 5-Methyl-1-(phenylsulfonylamino)-1H-[1,2,3]-triazole-4-carboxylic Acid Ethyl Ester
We reported experimental and theoretical investigation of conformers of 1,2,3-triazole derivatives, substances of exclusively synthetic origin, subject of extensive studies, because of several biological properties, such as antiviral, antimicrobial and antileishmaniasis. We reported molecular/supramolecular X-ray structures of antiophidian compounds I and II
J. Braz. Chem. Soc.. Publicado em: 2020-05
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10. BIOMECHANICAL PROPERTIES OF WOLFBERRY PLANT ORGANS
ABSTRACT To improve the picking rate and reduce the wrong picking rate of the existing wolfberry harvesting machinery, in this study, the binding force and physical appearance of the immature fruit stalk, mature fruit stalk, flower, and leaf were studied to guide the designing of new-generation wolfberry harvesting machinery and lay theoretical foundation fo
Eng. Agríc.. Publicado em: 2020-04
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11. Structural Study of Phenolic Acids by Triple Quadrupole Mass Spectrometry with Electrospray Ionization in Negative Mode and H/D Isotopic Exchange
This work reports the theoretical and experimental study of fragmentation reactions in the gas phase of five phenolic acids using triple quadrupole mass spectrometry by electrospray ionization in negative ionic mode, as well as the isotope exchange experiments. MS/MS spectra were analyzed to suggest the fragmentation mechanisms, while theoretical calculation
J. Braz. Chem. Soc.. Publicado em: 2020-02
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12. Experimental and Theoretical Study of LiMn2O4 Synthesized by the Solution Combustion Method Using Corn Starch as Fuel
Lithium manganese oxide, LiMn2O4, was synthesized in two temperature stages, where the first consisted by an ecofriendly solution combustion method at 300 °C. Finally, the as-burned powders were thermal treated at 500 and 700 °C. The structural and morphological changes were evaluated by the Rietveld method and density functional theory (DFT) calculations.
J. Braz. Chem. Soc.. Publicado em: 2020-02