Search results for "bolas"

showing 3 items of 3 documents

La situation actuelle de la protection du droit à la terre de las communautés 'quilombolas' et futurs défis

2016

Resumo: A construção da nação brasileira atravessou o período da escravidão, que, ao desaparecer, não incluiu o negro de maneira efetiva na sociedade. Desde o final do século XX, as reivindicações desses grupos se tornaram frequentes, gerando uma política compensatória, refletida no contexto legislativo. Nesse sentido, o objetivo deste artigo é examinar a efetividade do direito das comunidades quilombolas aos títulos das terras por elas habitadas. Para isso, a proposta de Emenda Constitucional 215/2000 será analisada. Abstract: The construction of the Brazilian nation went through the period of slavery. Once it was abolished, black people were not included effectively in society. Since the …

H1-99derechos sobre la tierradireito à terraright to landdroits fonciersproposition d'amendement constitutionnel 215/2000communautés quilombolasSocial sciences (General)proposta de emenda constitucional 215/2000comunidades quilombolasPolitical scienceproposed constitutional amendment 215/2000Current (fluid)quilombo communitiesEnvironmental planningpropuesta de enmienda constitucional 215/2000
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Half-width plots, a simple tool to predict peak shape, reveal column kinetics and characterise chromatographic columns in liquid chromatography: Stat…

2013

Peak profiles in chromatography are characterised by their height, position, width and asymmetry; the two latter depend on the values of the left and right peak half-widths. Simple correlations have been found between the peak half-widths and the retention times. The representation of such correlations has been called half-width plots. For isocratic elution, the plots are parabolic, although often, the parabolas can be approximated to straight-lines. The plots can be obtained with the half-widths/retention time data for a set of solutes experiencing the same kinetics, eluted with a mobile phase at fixed or varying composition. When the analysed solutes experience different resistance to mas…

Peak profiles in chromatography are characterised by their height position width and asymmetry; the two latter depend on the values of the left and right peak half-widths. Simple correlations have been found between the peak half-widths and the retention times. The representation of such correlations has been called half-width plots. For isocratic elution the plots are parabolic although often the parabolas can be approximated to straight-lines. The plots can be obtained with the half-widths/retention time data for a set of solutes experiencing the same kinetics eluted with a mobile phase at fixed or varying composition. When the analysed solutes experience different resistance to mass transfer the plots will be solute dependent and should be obtained with the data for each solute eluted with mobile phases at varying composition. The half-width plots approach is a simple tool that facilitates the prediction of peak shape (width and asymmetry) with optimisation purposes reveal the interaction kinetics of solutes in different columns and characterise chromatographic columns. This work shows half-width plots for different situations in isocratic elution including the use of different flows the effect of temperature the modification of the stationary phase surface by an additive the existence of specific interactions within the column and the comparison of columns. The adaptation to gradient elution is also described. Previous knowledge on half-width plots is structured and analysed to which new results are added.Work (thermodynamics)Column characterisationmedia_common.quotation_subjectKineticsLiquid chromatographyAnalytical chemistryHalf-widthsInteraction kineticsBiochemistryAsymmetryAnalytical ChemistryPeak shapeColumn (typography)Position (vector)Mass transferPhase (matter)media_commonChromatographyElutionChemistryOrganic ChemistryGeneral MedicineModels TheoreticalKineticsPredictionChromatography LiquidJournal of Chromatography A
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Structural and Transport Properties of Bola C-16 Micelles in Water and in Aqueous Electrolyte Solutions

2003

Aqueous solutions containing a bolaform surfactant [R,ω-(4,7,10,13-pentaoxa-16-azacyclooctadecane)- hexadecane], with and without electrolytes have been investigated as a function of surfactant concentration and ionic strength. Small angle neutron scattering (SANS), NMR self-diffusion, and other physical-chemical methods were used. From the analysis of SANS data it was inferred that in water the surfactant forms slightly charged ellipsoidal micelles, because of the partial hydrolysis of amino groups. The aggregates grow with the increase of concentration, becoming more elongated. Due to the selective complexing ability of aza crown ether units, significant differences were observed upon add…

chemistry.chemical_classificationAqueous solutionAggregation numberChemistryInorganic chemistryElectrolyteMicellebolasSurfaces Coatings and FilmsPulmonary surfactantMicelles SANS Bolaform surfactantIonic strengthmixed surfactantssaxsCritical micelle concentrationMaterials Chemistrybolas; mixed surfactants; saxs; sdsPhysical and Theoretical ChemistrysdsCrown etherThe Journal of Physical Chemistry B
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