Pseudoplastic
Mostrando 13-24 de 66 artigos, teses e dissertações.
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13. Use of Opuntia ficus-indica (L.) Mill extracts from Brazilian Caatinga as an alternative of natural moisturizer in cosmetic formulations
ABSTRACT The aim of this work was the obtainment of Opuntia fícus-indica (L.) Mill extract for the development of cosmetic formulations and in vivo evaluation of its moisturizing effects. The formulations were tested for preliminary and accelerated stability. Organoleptic characteristics, pH values and rheological behavior were assessed. The evaluation of m
Braz. J. Pharm. Sci.. Publicado em: 2016-09
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14. Whole and crushed nutlets of chia (Salvia hispanica) from Mexico as a source of functional gums
The objective of this study was to characterize the chemical and functional properties of Mexican chia (Salvia hispanica) gums extracted from defatted whole and crushed nutlets using the Soxhlet and SFE-CO2 methods. Chia gums have interesting chemical and functional properties for the food industry. The oil and gum yields were in the range of 1.98-16.42% and
Food Sci. Technol. Publicado em: 2014-12
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15. Funcionalización de polietileno de baja densidad con anhídrido maleico en estado fundido
In this study, low density polyethylene (LDPE) was modified with maleic anhydride (AM) in the molten state by using different concentrations of dycumil peroxide (DCP) (0.25, 0.50, 0.75 and 1.0 %). The materials obtained were characterized by gel content, acid-base titrations, infrared spectroscopy (IR), differential scanning calorimetry (DSC), thermogravimet
Polímeros. Publicado em: 2014
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16. An investigation of the behavior of a classifying hydrocyclone with pseudoplastic fluids
The procedure usually employed for specifying a set of hydrocyclones used in Newtonian fluid-solid separation processes can be extended to the case of non-Newtonian fluids. The apparent viscosity, µapp, is the link between the two cases, and can be evaluated from the knowledge of the shear stress function, S, and the characteristic rate of shear, λ*. In or
Braz. J. Chem. Eng.. Publicado em: 2013-12
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17. Bioconversion from crude glycerin by Xanthomonas campestris 2103: xanthan production and characterization
The production and rheological properties of xanthan gum from crude glycerin fermentation, a primary by-product of the biodiesel industry with environmental and health risks, were evaluated. Batch fermentations (28 °C/250 rpm /120 h) were carried out using crude glycerin, 0.01% urea and 0.1% KH2PO4, (% w/v), and compared to a sucrose control under the same
Braz. J. Chem. Eng.. Publicado em: 2013-12
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18. Flow of a Williamson fluid over a stretching sheet
In the present article, we have examined the two dimensional flow of Williamson fluid model over a stretching sheet. The governing equations of pseudoplastic Williamson fluid are modelled and then simplified by using similarity transformations and boundary layer approach. The reduced equations are then solved analytically with the help of homotopy analysis m
Braz. J. Chem. Eng.. Publicado em: 2013-09
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19. Rheology of spreadable goat cheese made with autochthonous lactic cultures differing in their ability to produce exopolysaccharides
The aim of this study was to compare the rheology of spreadable cheeses elaborated with autochthonous lactic starter cultures without the addition of exopolysaccharide-producing strain in the same starter with exopolysaccharide-producing strain. From a rheological standpoint, both samples were characterized as weak viscoelastic gels and pseudoplastic product
Food Sci. Technol. Publicado em: 10/05/2013
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20. Formulation and characterization of poloxamer 407®: thermoreversible gel containing polymeric microparticles and hyaluronic acid
The influence of the composition and preparation method on the sol-gel transition temperature (Tsol-gel) and rheological response of poloxamer-based formulations was determined. Manual and more complex mechanical stirring were found to provide similar results. In addition, a linear dependence of Tsol-gel on the poloxamer content was observed in the range of
Quím. Nova. Publicado em: 2013
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21. Distribuição do tempo de residência e letalidade no processamento térmico contínuo de líquidos com escoamento laminar não ideal em trocadores bitubulares. / Residence time distribution and lethality in the continuous thermal processing of liquids with non ideal laminar flow in bitubular exchangers.
Tubular heat exchangers are widely used for thermal processing of viscous liquid foods because they have larger hydraulic diameters than the plate heat exchangers. The calculation of lethality in this type of exchanger is directly related to velocity profile and the residence time distribution (RTD). For the laminar flow of viscous fluids, Newtonian and non-
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 02/03/2012
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22. Thermal and rheological behavior of reactive blends from metallocene olefin elastomers and polypropylene
Reactive blends of metallocene polyolefin elastomers (POE)/polypropylene (PP) with 60/40 composition were prepared with an organic peroxide, 2,5-dimethyl-2,5-di-(t-butylperoxy)hexane, and a bis-azide derivative, diphenyloxid-4,4'-bis(sulfonylazide) (BSA). Ethylene-1-butene (EB) and ethylene-1-octene (EO) copolymers and elastomeric polypropylene (ePP) were us
Polímeros. Publicado em: 05/06/2012
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23. A stabilized finite element method to pseudoplastic flow governed by the Sisko relation
In this work, a consistent stabilized mixed finite element formulation for incompressible pseudoplastic fluid flows governed by the Sisko constitutive equation is mathematically analysed. This formulation is constructed by adding least-squares of the governing equations and of the incompressibility constraint, with discontinuous pressure approximations, allo
Computational & Applied Mathematics. Publicado em: 2012
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24. Multiple emulsions containing amazon oil: açaí oil (Euterpe oleracea)
The aim of this work was to formulate O/W/O multiple emulsions containing açaí oil as a model system and to evaluate their physical stability and in vivo Sun Protection Factor (SPF). Multiple emulsions are complex dispersion systems, known also as, "emulsions of emulsions". These emulsion systems, have significant potential in the cosmetic industry. Euterp
Revista Brasileira de Farmacognosia. Publicado em: 03/06/2011