A Comparison of the Effect of Temperature on the Rheological Properties of Diutan and Rhamsan Gum Aqueous Solutions

The rheological properties exhibited by gums make its use in applications interesting, such as foods, cosmetics, enhanced oil recovery, or constructions materials. Regardless of application field, the effect of temperature on these properties is of great importance, since these properties can be modified and cause the gum not to be useful for those conditions. Diutan and rhamsan gums are biopolymers, belonging to the sphingans, with similar structures which differ in the substituents of their side chains. It is known that both gums exhibit suitable viscoelastic properties and flow behavior when used as a stabilizer, gelling agent, or thickener. Both gums are widely used in food industry, personal care products, construction materials, oil operations, etc. For this reason, to know the effect of the temperature on their rheological properties is very helpful. For this purpose, small amplitude oscillatory shear measurements and flow curves, as a function of the temperature from 10 C to 60 C, have been performed, and the results obtained for both gums compared. The obtained results provide interesting information from an industrial point of view, since they reveal that the rheological properties remained almost unaltered in the temperature range assessed with diutan gum aqueous solutions, being slightly more viscous and viscoelastic than rhamsan gum solutions.Spanish Ministerio de Economía y Competitividad (MINECO) and FEDER, UE project CTQ2015-70700-

A Comparison of the Effect of Temperature on the Rheological Properties of Diutan and Rhamsan Gum Aqueous Solutions

The rheological properties exhibited by gums make its use in applications interesting, such as foods, cosmetics, enhanced oil recovery, or constructions materials. Regardless of application field, the effect of temperature on these properties is of great importance, since these properties can be modified and cause the gum not to be useful for those conditions. Diutan and rhamsan gums are biopolymers, belonging to the sphingans, with similar structures which differ in the substituents of their side chains. It is known that both gums exhibit suitable viscoelastic properties and flow behavior when used as a stabilizer, gelling agent, or thickener. Both gums are widely used in food industry, personal care products, construction materials, oil operations, etc. For this reason, to know the effect of the temperature on their rheological properties is very helpful. For this purpose, small amplitude oscillatory shear measurements and flow curves, as a function of the temperature from 10 °C to 60 °C, have been performed, and the results obtained for both gums compared. The obtained results provide interesting information from an industrial point of view, since they reveal that the rheological properties remained almost unaltered in the temperature range assessed with diutan gum aqueous solutions, being slightly more viscous and viscoelastic than rhamsan gum solutions

Experiencias de educación indígena en Colombia : entre prácticas pedagógicas y políticas para la educación de grupos étnicos

Este libro presenta un análisis de las políticas educativas para y con grupos étnicos en Colombia, especialmente la educación de pueblos indígenas. Utiliza como fuentes para este análisis voces del movimiento indígena, jurisprudencia y academia. De otra parte, analiza tres experiencias educativas, a partir de un trabajo de campo en escuelas de educación propia en Colombia desde las cuales se expresa la relación entre dos categorías: política educativa (Nacional, Municipal,Comunitaria e Institucional) y pedagogía (aspectos curriculares, de formación de maestros, y administrativos). Además, se presenta una experiencia de formación docente en el marco de la interculturalidad urbana, proceso desarrollado para la formación de maestros de jardines indígenas en la ciudad de Bogotá. El grupo de investigación Equidad y Diversidad en Educación (Universidad Pedagógica Nacional y Universidad Distrital Francisco José de Caldas) espera con este libro aportar al reconocimiento y análisis de otras formas de hacer educación y desde allí a relevar los proyectos de lucha en defensa de lo propio que no solo respetan sino que intentan darle sentido y permanencia a lo que por otros ha sido catalogado como diferente.Presentación - Sandra Patricia Guido Guevara 11 Prólogo 15 Capítulo I Pueblos indígenas y políticas educativas en Colombia: encantos y desencantos Sandra Patricia Guido Guevara Hollman Andrés Bonilla García 19 Capítulo 2 Experiencia educativa resguardo indígena de Ambaló. Escuela Ayanku´c Angie Linda Benavides Cortés 57 Capítulo 3 La experiencia de CIFIWUAN, entre la innovación pedagógica y la lucha política Gabriel Antonio Lara Guzmán 85 Capítulo 4 La Escuela Normal Superior Indígena de Uribia. Una experiencia desde la pedagogía de la afirmación cultural Diana Patricia García Ríos María del Socorro Jutinico Fernández 103 Capítulo 5 Educación inicial y diversidad cultural. Una experiencia de formación de maestros de los jardines infantiles indígenas de Bogotá Ingrid Sissy Delgadillo Cely Diana Patricia García Ríos Betty Sandoval Guzmán 14