Separation Reactions
Mostrando 1-12 de 151 artigos, teses e dissertações.
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1. UMA PROPOSTA PARA O ENSINO DE LABORATÓRIO DE QUÍMICA ANALÍTICA QUALITATIVA
Teaching laboratory of qualitative analytical chemistry is still a controversial issue in chemistry courses. However, important researchers and educators in chemistry recognized and highlighted the importance that the contents of this discipline represent in the formation of chemists, once it can provide handling and understanding of microscopic phenomena ba
Quím. Nova. Publicado em: 2021-04
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2. AN APPROACH BASED ON ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY TO STUDY THE GLYCEROL/BIODIESEL GRAVITY SEPARATION
In this study, electrochemical impedance spectroscopy (EIS) is evaluated as a novel application in the biodiesel purification process. EIS is proposed as a tool to study the behavior of charge carriers produced from side reactions or dissociations of some impurities during the gravitational separation of glycerol dispersed in crude biodiesel after the transe
Quím. Nova. Publicado em: 2020-12
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3. Synthesis of Hybrid Monolithic Columns Using a Click Chemistry Reaction for Application in Capillary Liquid Chromatography
Hybrid monolithic columns present characteristics of both silica and organic monoliths, such as good mechanical properties, wide pH tolerance, high permeability and stability and little swelling or shrinkage. A common way to prepare this type of material is by using alkoxysilanes and organic monomers via the sol-gel process and click chemistry reactions. In
J. Braz. Chem. Soc.. Publicado em: 24/10/2019
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4. Membranas Compuestas: propiedades superficiales y estabilidad térmica
ABSTRACT The composite membranes were manufactured with crosslinking poly(vinyl alcohol) on polyethersulfone porous membranes by coating process. PES membranes were exposed to air plasma for the purpose of surface modification. The coating of the support membrane was carried out by using a polymer matrix with a crosslinking agent. The physico-chemical proper
Matéria (Rio J.). Publicado em: 19/07/2018
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5. Mini-channel Two Phase Flow of Hydrogen Peroxide: Decomposition with Silver Catalyst
ABSTRACT Hydrogen peroxide is a chemical compound which is commonly used as a disinfectant at lower concentrations. The chemical is called as a green propellant for space applications. Water and oxygen are the products after self-decomposition of the compound at higher concentrations. The reaction rate at lower concentrations can be enhanced by using catalys
J. Aerosp. Technol. Manag.. Publicado em: 14/06/2018
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6. Coupling DLLME-CE for the Stereoselective Analysis of Venlafaxine and Its Main Metabolites after Biotransformation by Fungi
Fungal biotransformations have become very important in the study of chiral drugs because the reactions performed by these microorganisms may be enantioselective. However, analyses of analytes present in liquid culture medium have proved to be very difficult due to the complexity of this matrix. The aim of this work was to couple dispersive liquid-liquid mic
J. Braz. Chem. Soc.. Publicado em: 2015-09
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7. Nanoparticles containing curcuminoids (Curcuma longa): development of topical delivery formulation
Solid lipid nanoparticles incorporating Curcuma longa L., Zingiberaceae, curcuminoids were produced by the hot melt emulsion method. A Box–Behnken factorial design was adopted to study the nanoparticles production at different levels of factors such as the percentage of curcuminoids, time of homogenization and surfactant ratio. The optimized nanoparticles
Rev. bras. farmacogn.. Publicado em: 2015-02
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8. Metal nanoparticles/ionic liquid/cellulose: polymeric membrane for hydrogenation reactions
Rhodium and platinum nanoparticles were supported in polymeric membranes with 10, 20 and 40 µm thickness. The polymeric membranes were prepared combining cellulose acetate and the ionic liquid (IL) 1-n-butyl-3-methylimidazolium bis(trifluoromethane sulfonyl)imide (BMI.(NTf)2. The presence of metal nanoparticles induced an increase in the polymeric membrane
Polímeros. Publicado em: 18/04/2014
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9. Solid-liquid equilibrium data of amoxicillin and hydroxyphenylglycine in aqueous media
The enzymatic synthesis of amoxicillin is catalyzed by Penicillin G Acylase (PGA). As byproducts, hydroxyphenylglycine and alcohol are also formed from hydrolytic reactions and antibiotic synthesis, respectively. The design of this process should be directed to promote the synthesis reaction. At the same time, it is necessary to reduce the hydrolytic reactio
Braz. J. Chem. Eng.. Publicado em: 2013-03
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10. Methylparaben concentration in commercial Brazilian local anesthetics solutions
OBJECTIVE: To detect the presence and concentration of methylparaben in cartridges of commercial Brazilian local anesthetics. MATERIAL AND METHODS: Twelve commercial brands (4 in glass and 8 in plastic cartridges) of local anesthetic solutions for use in dentistry were purchased from the Brazilian market and analyzed. Different lots of the commercial brands
J. Appl. Oral Sci.. Publicado em: 2012-08
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11. New perspective on the pathophysiology of panic: merging serotonin and opioids in the periaqueductal gray
Panic disorder patients are vulnerable to recurrent panic attacks. Two neurochemical hypotheses have been proposed to explain this susceptibility. The first assumes that panic patients have deficient serotonergic inhibition of neurons localized in the dorsal periaqueductal gray matter of the midbrain that organize defensive reactions to cope with proximal th
Brazilian Journal of Medical and Biological Research. Publicado em: 2012-04
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12. Miniprojeto para ensino de química geral experimental baseado na fermentação do caldo de cana-de-açúcar
This paper describes a five-week mini-project for a general chemistry laboratory course. Activities are included preparations of ethanol and sucrose solutions, calculation of concentrations, determination of densities with densimeters, sugarcane juice fermentation with CO2 capture in alkaline solution, distillation, and determination of amounts of ethanol an
Quím. Nova. Publicado em: 2012