Cosolvent
Mostrando 13-24 de 58 artigos, teses e dissertações.
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13. Extração supercrítica do óleo de linhaça: construção do extrator, estudo de parâmetros de processo, avaliação química e antioxidante do produto
The aim of the present study was to extract vegetable oil from brown linseed (Linum usitatissimum L.), determine fatty acid levels, the antioxidant capacity of the extracted oil and perform a rapid economic assessment of the SFE process in the manufacture of oil. The experiments were conducted in a test bench extractor capable of operating with carbon dioxid
Publicado em: 2009
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14. FE(III) AS ELECTRON ACCEPTOR FOR GASOLINE-ETHANOL BIODEGRADATION IN TROPICAL RESIDUAL SOIL / FE(III) COMO ACEPTOR DE ELÉTRONS NA BIODEGRADAÇÃO DE GASOLINA-ETANOL EM SOLO TROPICAL RESIDUAL
Gasoline monoaromatic hydrocarbons (BTEX) have been detected in aquifers due to storage tank spills from gas stations that lead to their consequent dissolution on groundwater. An aggravating factor in Brazil is ethanol being used as additive to gasoline, promoting an increase on pollutants percolation in soil since it works as co-solvent and is preferentiall
Publicado em: 2009
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15. Efeitos de terpenos nas membranas de estrato córneo estudados por ressonância paramagnética eletrônica / Effects of terpenes on the stratum corneum membranes studied by electron paramagnetic resonance
The interaction of the skin penetration enhancers DL-menthol, -terpineol, 1,8-cineole and (+)-limonene with membranes of the uppermost skin layer, the stratum corneum (SC) and with multilamellar vesicles from 1,2-dipalmitoyl-sn-glycero-3-phosphaticylcholine (DPPC)is investigated by electron paramagnetic resonance (EPR) spectroscopy using spin-labeled
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 18/02/2008
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16. Extraction of caffeine, chlorogenic acids and lipids from green coffee beans using supercritical carbon dioxide and co-solvents
The paper reports on experimental data on the extraction of caffeine, coffee oil and chlorogenic acids from green coffee beans using pure supercritical CO2 and supercritical CO2 modified with ethanol (5% w/w) and isopropyl alcohol (5% w/w) at 50 and 60ºC and 15.2 24.8 e 35.2 MPa. In this study extraction kinetics were obtained for all assays i.e. samples we
Brazilian Journal of Chemical Engineering. Publicado em: 2008-09
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17. Extraction of bixin from annatto seeds using supercritical carbon dioxide
The solubility of 93% pure bixin in supercritical carbon dioxide (SC-CO2) and of the bixin present in annatto seeds (Bixa orellana L.) was measured. For the seeds, the measurements were made in a temperature range from 30 to 50ºC and pressure between 10 and 35 MPa and for the pure bixin, at 40ºC from 10 to 35 MPa. The main pigments of annatto seeds are bix
Brazilian Journal of Chemical Engineering. Publicado em: 2008-06
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18. Extraction of pilocarpine and epiisopiloturine from jaborandi (pilocarpus microphyllus) using processes involving supercritical solvents / Extração de pilocarpina e episopiloturina de jaborandi utilizando processos envolvendo solventes supercriticos
Pilocarpine is an alkaloid found only in jaborandi leaves (Pilocarpus microphyllus), a native tree of Brazil, and is widely used in the treatment of glaucoma and xerostomia (dry mouth). Epiisopiloturine, another alkaloid also found in jaborandi has a similar biological activity, acting by different mechanisms. This research evaluated the applicability of the
Publicado em: 2008
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19. Phase equilibrium and structural characterizarion of systems composed by polyanions and cationic surfactants / Equilibrio de fases e caracterização estrutural de sistemas contendo polianions e surfatantes cationicos
Polieletrólitos associam-se fortemente com surfatantes de carga oposta em meio aquoso, levando a uma separação de fases que resulta em uma fase concentrada, rica em polieletrólito e surfatante, em equilíbrio com uma fase diluída constituída pelos contra-íons. A fase concentrada pode ser constituída de interessantes estruturas supramoleculares advind
Publicado em: 2008
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20. Desviaciones al modelo logarítmico-lineal en la solubilidad de ibuprofén y naproxén en mezclas cosolventes propilenoglicol-agua
The deviations observed in the solubility of ibuprofen (IBP) and naproxen (NAP) in propylene glycol (PG) + water (W) cosolvent mixtures with respect to the logarithmic-linear model proposed by Yalkowsky have been analyzed at 25.00 ± 0.05 ºC. Negative deviations were obtained in all cosolvent compositions for both drugs; they were greater for IBP. Another t
Química Nova. Publicado em: 2007
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21. Estudo dos parÃmetros influentes no sistema de hidrogenaÃÃo eletrocatalÃtica com Ãnodo de sacrifÃcio, utilizando planejamento fatorial como ferramenta de anÃlise
A full factorial design 24 was used in the analysis of the main factors that can influence the electrocatalytic hydrogenation of the (+)-pulegone, using a Ni sacrificial anode (HECAS). The following factors of control had been appraised: co-solvent (H2O/MeOH or H2O/ethylene glycol (1:1)), temperature (25oC or 50oC), cathodic material (Cu or Fe/Ni (64:36) all
Publicado em: 2007
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22. AvaliaÃÃo fungitÃxica e caracterizaÃÃo quÃmica dos Ãleos essenciais e extratos obtidos apÃs diferentes processos de extraÃÃo de Cipà Vick (Tanaecium Nocturnum) e JoÃo Brandim (Piper Piscatorum) / Evaluation of fungitoxic activity and chemical characterization of the essential oils obtained after different processes of extraction of cipà vick (Tanaecium nocturnum) and joÃo-brandim (Piper piscatorum).
The chemical characterization by IR, GC-MS and GC-FID of essential oils and extracts obtained from Piper piscatorum and Tanaecium nocturnum, plant species native to the state of Acre, by different extraction processes and the evaluation of the toxicity to Aspergillus flavus were performed. The study involved four experiments. In the first, the efficiency of
Publicado em: 2007
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23. Impregnation of pet films and PHB granules with curcumin in supercritical CO2
The process of dyeing poly(ethylene terephthalate) - PET films at 50, 60 and 65ºC and poly(hydroxybutyrate) - PHB granules at 60, 70 and 80ºC using supercritical carbon dioxide (scCO2) as solvent and ethanol as cosolvent was studied by DSC, TGA analysis and measurements of shrinkage to determine the morphological modifications caused by the scCO2 treatment
Brazilian Journal of Chemical Engineering. Publicado em: 2006-06
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24. Thermodynamic study of the solubility of acetaminophen in propylene glycol + water cosolvent mixtures
Baseado nas equações de van't Hoff e Gibbs, as funções termodinâmicas energia de Gibbs, entalpia e entropia de solução, mistura e solvatação de acetaminofen em misturas dos solventes propileno glicol + água (PG + W), foram avaliadas por medidas de solubilidade em diversas temperaturas. A solubilidade foi maior para 100% de PG em todas as temperatur
Journal of the Brazilian Chemical Society. Publicado em: 2006-02