Ionic Concentration
Mostrando 13-24 de 779 artigos, teses e dissertações.
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13. THERMAL CONDUCTIVITY ENHANCEMENT OF AQUEOUS IONIC LIQUID AND NANOPARTICLE SUSPENSION
Abstract In the present study, the thermal conductivities of ionic liquid + water in the concentrations 0.1-0.6 %w/w and temperatures (302.5-337.9 K) are determined. The thermal conductivity of aqueous 1-butyl-3-methylimidazolium bromide declined with increasing concentration and temperature. A quadratic model is developed for predicting the thermal conducti
Braz. J. Chem. Eng.. Publicado em: 30/09/2019
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14. Perfil metabólico de vacas Holandês e mestiças Holandês x Jersey no periparto
RESUMO O objetivo do presente trabalho foi determinar e comparar o perfil metabólico de vacas Holandês (H) e mestiças Holandês x Jersey (HxJ) no periparto. Avaliaram-se 24 vacas, sendo 11 vacas Holandês e 13 mestiças Holandês x Jersey. Semanalmente, coletou-se sangue para a determinação das concentrações séricas de glicose, beta-hidroxibutirato (
Arq. Bras. Med. Vet. Zootec.. Publicado em: 14/06/2019
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15. Liquid-liquid equilibria in aqueous two-phase ethanol/salt systems at different temperatures and their application to anthocyanins extraction
Abstract Aqueous two-phase systems (ATPS) are formed by mixtures of chemical species that, under certain conditions, separate into two immiscible phases, with water as the major component in global terms and, at lower concentrations, polymers, salts, ionic liquids and alcohols, depending on the system type. Different parameters influence ATPS equilibrium suc
Food Sci. Technol. Publicado em: 16/05/2019
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16. Stability of Nanocomposite Edible Films Based on Polysaccharides and Vitamin C from Agroindustrial Residue
The agroindustrial residue from the production of acerola pulp is rich in residual vitamin C. Thus, aiming its extraction and stabilization, this work proposed the nanoparticle (NP) encapsulation via ionic gelation with subsequent preparation of nanocomposites (NC) film based on galactomannan matrix. NP were characterized and their stabilities were evaluated
Mat. Res.. Publicado em: 18/04/2019
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17. MEASURING THE CONDUCTIVITY OF VERY DILUTE ELECTROLYTE SOLUTIONS, DROP BY DROP
Undergraduate experiments on ionic conductivity are common practice in general chemistry and advanced physical chemistry laboratories. Often, the conductivities are measured for solutions prepared for various salts, in a range of concentrations, and the relationship between solution conductivity and concentration is interpreted in terms of the Kohlrausch law
Quím. Nova. Publicado em: 2018-07
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18. SORÇÃO DE CO2 UTILIZANDO LÍQUIDO IÔNICO ADITIVADO COM EXTENSORES DE ÁREA SUPERFICIAL
The study of environmentally friendly CO2 sorption agents are growing due to the need of mitigate this gas from atmosphere. Ionic Liquids (ILs) present the advantage of having low vapor pressures and being chemically and thermally stable. Besides, their properties can be designed by varying the groups of the cation or anion. Yet, these compounds present a lo
Quím. Nova. Publicado em: 2018-06
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19. POLÍMERO BIODEGRADÁVEL ANTIMICROBIANO ATRAVÉS DA ADITIVAÇÃO COM COMPOSTOS À BASE DE ZINCO
Antimicrobial packaging is a promising type of active packaging, which has an antimicrobial agent incorporated into the polymer matrix, capable to eliminate or inhibit deteriorating and/or pathogenic microorganisms. The zinc compounds are antimicrobial agents commonly used to confer this feature. The objective of this work was to evaluate the antimicrobial a
Quím. Nova. Publicado em: 2018-04
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20. Exploiting Cork as Biosorbent Extraction Phase for Solid-Phase Microextraction to Determine 3-(4-Methylbenzylidene)camphor and 2-Ethylhexyl 4-(Dimethylamino)benzoate in River Water by Gas Chromatography-Mass Spectrometry
In this study, a method for the determination of 3-(4-methylbenzylidene)camphor (4-MBC) and 2-ethylhexyl 4-(dimethylamino)benzoate (OD-PABA) in river water samples employing cork as the SPME (solid-phase microextraction) fiber was developed. The extraction parameters optimized were pH, ionic strength and extraction time and temperature. For the extraction st
J. Braz. Chem. Soc.. Publicado em: 2017-12
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21. Application of Response Surface Modeling and Chemometrics Methods for the Determination of Ofloxacin in Human Urine Using Dispersive Liquid-Liquid Microextraction Combined with Spectrofluorimetry
Dispersive liquid-liquid microextraction (DLLME) and spectrofluorimetry, coupled with chemometrics methods, are proposed in this work for the pre-concentration and determination of ofloxacin concentration in spiked human urine. Chloroform and acetonitrile were selected as the extraction and dispersive solvents by the one-variable-at-a-time process. The Box-B
J. Braz. Chem. Soc.. Publicado em: 2017-12
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22. Lime and calcium-magnesium silicate in the ionic speciation of an Oxisol
ABSTRACT Plant residues and certain fertilizers accelerate soil acidification and increase the levels of aluminum-Al+3 in soils under no-tillage (NT). Silicates act as acidity amendments and as a source of silicon as in H4SiO4. An increase in the pH of soil solution causes the deprotonation of H4SiO4 and generates the anionic form (H3SiO4−). The aim of thi
Sci. agric. (Piracicaba, Braz.). Publicado em: 2017-08
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23. Direct Determination of N-Nitrosoglyphosate in Technical Glyphosate Using Ion Chromatography with UV Detection
The official method for analyzing N-nitrosoglyphosate (NNG), a relevant impurity, in glyphosate matrix demands complicated instrumentation and operating conditions not available in many laboratories. In this work, we developed a direct, simple, selective and sensitive ion chromatography (IC) method with UV detection for the determination of NNG in samples of
J. Braz. Chem. Soc.. Publicado em: 2017-07
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24. VALIDAÇÃO DE MÉTODO POR MEFS-HS/CG-EM PARA DETERMINAÇÃO DE CARBARIL EM PLASMA SANGUÍNEO
The aim this research is to develop a HS-SPME/GC-MS method to analyze the carbaryl in blood plasma samples of the rural workers, who live round the perimeter of Chapada do Apodi-CE. This was achieved by chromatographic signal of the 1-naftol, degradation product of carbaryl with the intention of evaluating the degree of exposure of the workers to pesticides,
Quím. Nova. Publicado em: 2017-06