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Historias de la Universidad Azul
(Universidad de Chile, 2017)
el fin de recoger relatos, tradiciones e historias de cada una de estas unidades: ya sea por sus aportes al desarrollo del país, su participación en transformaciones y conflictos en la sociedad o importantes avances en la cultura y la investigación...
Antecedentes para una historia cultural la Universidad de Chile, 1842-1901
(Universidad de Chile, Facultad de Filosofía y Humanidades, 1989)
pública; la de Ciencias Matemáticas y Físicas, la construc-
ción de obras y edificios públicos; la de Filosofía y Humanidades, dirigiría las
enseñanzas primaria y secundaria.
En 1843, se estableció que en los días de asistencia solemne, los empleados
de...
, matemáticas superiores y ciencias naturales tenían sus cátedras (por demás muy escasas) en el llamado Instituto Nacional", ... "En este plantel todos los cursos de instrucción superior estaban confundidos con los cursos de liceos y los elementales" ... 8...
, matemáticas superiores y ciencias naturales tenían sus cátedras (por demás muy escasas) en el llamado Instituto Nacional", ... "En este plantel todos los cursos de instrucción superior estaban confundidos con los cursos de liceos y los elementales" ... 8...
Ecología urbana de las ciudades intermedias chilenas
(2004)
y Magíster en Gestión y Planificación Ambiental de la Universidad
de Chile
2 Centro EULA de Ciencias Ambientales de la Universidad de Concepción
3 Departamento de Ciencias Sociales de la Universidad de La Frontera, Temuco
Proyecto Fondecyt 100828...
ambientes. La ecología urbana es analizada en cuanto a sus diferentes definiciones y como ciencia ecológica-social integrada, revisándose sus en y de la ciudad, así como las bases de la integración entre la heterogeneidad espacial de los ecosistemas y las...
ambientes. La ecología urbana es analizada en cuanto a sus diferentes definiciones y como ciencia ecológica-social integrada, revisándose sus en y de la ciudad, así como las bases de la integración entre la heterogeneidad espacial de los ecosistemas y las...
Indagación en el manual escolar: evidencias de formación a través de preguntas, para una ciudadanía científicamente informada
(Universidad de Chile, 2020)
La pregunta es uno de los mecanismos fundamentales que poseemos como humanos para relacionarnos con otros y con nuestro entorno. Como tal, es de suma relevancia en la interacción pedagógica y en la construcción de conocimiento. Este trabajo busca...
Diseño de emulsiones O/W en base a complejos solubles de proteínas de quínoa/polisacáridos aniónicos y catiónicos para su potencial uso como aderezos bajos en lípidos
(Universidad de Chile, 2019)
cambios en la estructura secundaria y terciaria de las proteínas de quínoa, producto de su interacción con los polisacáridos durante la formación de los complejos, y se identificó el tipo de interacciones intermoleculares involucradas en dicho proceso...
The general objective of this research was to obtain and characterize structural, physicochemical, rheological and texturally O/W emulsions stabilized by soluble complexes of quínoa proteins/anionic (alginate) and cationic (chitosan) polysaccharides, for their potential use as low-fat dressings. Initially, soluble complexes formed by quínoa proteins and sodium alginate (Q-Alg) and quínoa proteins and chitosan (Q-Qo) were developed at different combination ratios (4:1 to 1:4) and characterized structurally and physicochemically, determining its surface electric charge (Z-potential), its particle size, its conductivity and ionic strength and its thermal stability. Additionally, the presence of changes in the secondary and tertiary structure of quínoa proteins, as a result of their interaction with polysaccharides during complex formation, were determined, and the type of intermolecular interactions involved in this process were identified. Subsequently, aqueous phases of O/W emulsions were prepared from the quínoa proteins-alginate and quínoa proteins-chitosan soluble complexes and were rheologically characterized. From these dispersions, O/W emulsions were obtained at the same previously mentioned combination ratios and characterized, determining their flow behavior, their dynamic rheological behavior, their particle size distribution and their microstructure. Taking these data into consideration, the optimum ratio for each type of emulsion was selected, choosing the Q-Alg and Q-Qo 1:4 ratios. These selected emulsions were characterized according to the storage time (up to 1 month) and the temperature (5, 25 and 37°C) of the samples, determining their rheological properties (flow behavior and dynamic rheological behavior), their particle size distribution, microstructure, creaming stability and overall physical stability. Based on these results, the protein-polysaccharide system suitable for the preparation of the food dressing was selected, and it was prepared using the Q-Alg 1: 4 emulsion, a non-caloric flavor and colorant, and various natural spices. The nutritional composition and the caloric value of the prepared dressing was determined and this product was subjected to a consumer test to determine its acceptability. Among the most important findings of the present investigation were the feasibility of the formation of the Q-Alg and Q-Qo soluble complexes at pHs 6 and 5.5, respectively. These complexes proved to be obtained and stabilized through weak electrostatic interactions, hydrophobic interactions and hydrogen bonds in the case of the Q-Alg complexes, while in the case of the Q-Qo complexes, the main interactions were the electrostatic interactions and the hydrogen bridges. Additionally, it was observed that the 1:4, 2:3 and 3:2 ratios for the Q-Alg complexes and the 1:4 and 2:3 ratios for the Q-Qo complexes were the conditions under which the greatest interactions were achieved, and in all cases, the interaction of quínoa proteins with both polysaccharides produced changes in their secondary and tertiary structure. On the other hand, the Q-Alg and Q-Qo 1:4 emulsions had better rheological properties; and in the case of the Q-Alg 1:4 emulsions, they also showed smaller particle sizes, so they were selected as optimal for the chosen food application. However, Q-Alg 1:4 emulsions proved to be much more stable than Q-Qo 1:4 emulsions due to their higher viscosity, lower particle diameters, lower polydispersity, and the presence of the Q-Alg complexes that may have stabilized the emulsions by electrostatic and steric mechanisms, so they were selected for the dressing preparation. The developed food dressing proved to have a low lipid content, and could be labelled as a "reduced fat and calories product" according to the sanitary food regulations. In addition, the sensory characterization of the dressing indicated a high degree of acceptability of the product in all its sensory attributes, demonstrating that Q-Alg 1:4 emulsions can serve as a basis for the formulation of different types of healthy dressings with good sensory and rheological properties and stable during storage...
The general objective of this research was to obtain and characterize structural, physicochemical, rheological and texturally O/W emulsions stabilized by soluble complexes of quínoa proteins/anionic (alginate) and cationic (chitosan) polysaccharides, for their potential use as low-fat dressings. Initially, soluble complexes formed by quínoa proteins and sodium alginate (Q-Alg) and quínoa proteins and chitosan (Q-Qo) were developed at different combination ratios (4:1 to 1:4) and characterized structurally and physicochemically, determining its surface electric charge (Z-potential), its particle size, its conductivity and ionic strength and its thermal stability. Additionally, the presence of changes in the secondary and tertiary structure of quínoa proteins, as a result of their interaction with polysaccharides during complex formation, were determined, and the type of intermolecular interactions involved in this process were identified. Subsequently, aqueous phases of O/W emulsions were prepared from the quínoa proteins-alginate and quínoa proteins-chitosan soluble complexes and were rheologically characterized. From these dispersions, O/W emulsions were obtained at the same previously mentioned combination ratios and characterized, determining their flow behavior, their dynamic rheological behavior, their particle size distribution and their microstructure. Taking these data into consideration, the optimum ratio for each type of emulsion was selected, choosing the Q-Alg and Q-Qo 1:4 ratios. These selected emulsions were characterized according to the storage time (up to 1 month) and the temperature (5, 25 and 37°C) of the samples, determining their rheological properties (flow behavior and dynamic rheological behavior), their particle size distribution, microstructure, creaming stability and overall physical stability. Based on these results, the protein-polysaccharide system suitable for the preparation of the food dressing was selected, and it was prepared using the Q-Alg 1: 4 emulsion, a non-caloric flavor and colorant, and various natural spices. The nutritional composition and the caloric value of the prepared dressing was determined and this product was subjected to a consumer test to determine its acceptability. Among the most important findings of the present investigation were the feasibility of the formation of the Q-Alg and Q-Qo soluble complexes at pHs 6 and 5.5, respectively. These complexes proved to be obtained and stabilized through weak electrostatic interactions, hydrophobic interactions and hydrogen bonds in the case of the Q-Alg complexes, while in the case of the Q-Qo complexes, the main interactions were the electrostatic interactions and the hydrogen bridges. Additionally, it was observed that the 1:4, 2:3 and 3:2 ratios for the Q-Alg complexes and the 1:4 and 2:3 ratios for the Q-Qo complexes were the conditions under which the greatest interactions were achieved, and in all cases, the interaction of quínoa proteins with both polysaccharides produced changes in their secondary and tertiary structure. On the other hand, the Q-Alg and Q-Qo 1:4 emulsions had better rheological properties; and in the case of the Q-Alg 1:4 emulsions, they also showed smaller particle sizes, so they were selected as optimal for the chosen food application. However, Q-Alg 1:4 emulsions proved to be much more stable than Q-Qo 1:4 emulsions due to their higher viscosity, lower particle diameters, lower polydispersity, and the presence of the Q-Alg complexes that may have stabilized the emulsions by electrostatic and steric mechanisms, so they were selected for the dressing preparation. The developed food dressing proved to have a low lipid content, and could be labelled as a "reduced fat and calories product" according to the sanitary food regulations. In addition, the sensory characterization of the dressing indicated a high degree of acceptability of the product in all its sensory attributes, demonstrating that Q-Alg 1:4 emulsions can serve as a basis for the formulation of different types of healthy dressings with good sensory and rheological properties and stable during storage...
La importancia de la relación entre docentes y estudiantes para una profesora de educación secundaria
(Universidad de Chile, 2020)
entre docentes y estudiantes para una profesora de educación secundaria” planteándose el objetivo de conocer a la profesora guía del área de jefatura, profundizar en cómo orienta su trabajo en el aula y el proceso que ha vivido en el actual contexto de...
Ponderación de factores antropogénicos y naturales que causarían la subsidencia de terreno en la comuna de Tierra Amarilla, región de Atacama, Chile
(Universidad de Chile, 2016)
año 2013, el área urbana de la comuna de Tierra Amarilla presentó tres subsidencias de terreno de distintos tamaños. Los factores naturales ponderados que incidirían en las subsidencias son: la posible disolución de la roca subterránea, disminución de...
Procesos de reestructuración urbana y niveles de vulnerabilidad a amenazas naturales en una ciudad de tamano medio: La Serena, Chile
(2002)
Invest. Geogr. Chile, 36 (2002) 17
Procesos de reestructuracion urbana y niveles de vulnerabilidad a
amenazas naturales en una ciudad de tamano medio: La Serena, Chile (*)
Jorge Ortiz Veliz
jortiz@ uchile. cl...
costa del aumento del uso y consumo de recursos (suelo, agua, energia) generando un crecimiento no sustentable. En ocasiones, la poblacion ocupa espacios expuestos a ame- nazas naturales, desarrollandose barrios al margen del funcionamiento de la...
costa del aumento del uso y consumo de recursos (suelo, agua, energia) generando un crecimiento no sustentable. En ocasiones, la poblacion ocupa espacios expuestos a ame- nazas naturales, desarrollandose barrios al margen del funcionamiento de la...
Modelación geoestadística del contenido de carbono orgánico del suelo entre las regiones de Valparaíso y de Los Ríos, Chile
(Universidad de Chile, 2011)
-Kriging (CK)
Es una variación multivariable de Kriging (Ecuación 6), donde la predicción se realiza
tomando en cuenta, además de los datos de la propiedad de interés, los datos de propiedades
secundarias correlacionadas. Su cálculo se basa en la siguiente...
; nv es el número de variables secundarias, n j es el número de puntos de la j-ésima variable secundaria dentro del área de búsqueda, λi j es el peso asignado al i j-ésimo punto de la j-ésima variable secundaria, Z j(xi j) es el valor en el i j...
; nv es el número de variables secundarias, n j es el número de puntos de la j-ésima variable secundaria dentro del área de búsqueda, λi j es el peso asignado al i j-ésimo punto de la j-ésima variable secundaria, Z j(xi j) es el valor en el i j...
Análisis y recomendaciones para la continuidad de la iniciativa tus competencias en ciencias del programa Explora de Conicyt en establecimientos educacionales de Chile
(Universidad de Chile, 2014)
El Programa EXPLORA de CONICYT es un programa nacional de Educación no formal en Ciencia y Tecnología, creado en 1995 por la Comisión Nacional de Investigación Científica y Tecnológica CONICYT, cuya misión es contribuir a la creación de una cultura...