Propiedades psicométricas del Inventario de Cociente Emocional EQ-i : YV en alumnos superdotados y talentosos

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Juegos deportivos y emociones : propiedades psicométricas de la escala GES para ser aplicada en la Educación Física y el Deporte

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Propiedades métricas y estructura dimensional de la adaptación española de una escala de evaluación de competencia informacional autopercibida (IL-HUMASS)

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Propiedades psicom??tricas del cuestionario ActEval sobre la actividad evaluadora del profesorado universitario

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Conceptos y propiedades de probabilidad en libros de texto espa??oles de educaci??n primaria

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Propiedades psicom??tricas de la escala ARC-INICO para evaluar la autodeterminaci??n

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Influencia del proceso de reciclado sobre las propiedades de los materiales compuestos obtenidos por inyección de poliestireno reforzado con fibras lignocelulósicas

The objective of this research is to study the influence of several recycling cycles on the mechanical properties of four different materials made by the injection of polystyrene. The four materials studied have different characteristics. The first one is polystyrene (PS), the second one is polystyrene reinforced with hemp fibers (PSf), the third one is polystyrene reinforced with hemp fibers modified with AKD (PSft) and the last one is polystyrene reinforced with fiberglass (PSfv). With all these materials tensile strength, bending, hardness and impact is measured. After the measurement of these physical properties, materials are recycled to obtain new injection samples, and its physical properties are measured again. This process is repeated during 24 cycles. After each recycling cycle material physical properties are related with polystyrene molecular weight, melt flow, FTIR spectra and DSC. From reinforced materials, fibers are recovered and through microscopy and image analysis they are characterized to study the influence that recycling has on its structure.

El desarrollo de las propiedades textuales, como herramienta para la enseñanza de la producción de textos no literarios, en el décimo año de educación básica de los colegios fiscales de la parroquia Ignacio Flores de la ciudad de Latacunga, provincia de Cotopaxi

Para la enseñanza de la escritura, en nuestro país, durante muchos años, los maestros y maestras se han basado en la gramática estructural, sin ningún buen resultado, ya que esta da prioridad únicamente al aspecto formal de la escritura y es el caso particular de los colegios Luis Fernando Ruiz y Trajano Naranjo Iturralde. Por esta razón, el primer capítulo de esta propuesta se centra en un nuevo enfoque, el de la Gramática Textual, dando a conocer los planteamientos de cada uno de los lingüistas y pedagogos como: Noam Chomsky, Teun A.van Dijk, Daniel Cassany, entre otros, sobre los procesos de la producción de textos. Además se hace una reflexión sobre lo que es escribir, los procesos cognitivos de la escritura y la importancia de enseñar a partir de situaciones comunicativas en que se use la escritura. En el segundo capítulo se realiza un análisis de la información recogida respecto al proceso que siguen los docentes de Lengua y Literatura para la enseñanza de la producción textual. También se analiza las encuestas realizadas a los estudiantes sobre cómo aprenden a escribir y las producciones textuales de los mismos, aplicando cada una de las propiedades textuales. En el tercer capítulo se describe la nueva propuesta de la Gramática Textual en la producción de textos no literarios, siguiendo cada uno de los pasos para escribir, sugeridos por los expertos. Además se realiza un ejemplo de planificación para la construcción de una noticia con los estudiantes del décimo año de educación básica, en la que se hace hincapié en la responsabilidad que tiene el maestro como mediador para brindar el grado de ayuda que requiere el estudiante en la aplicación de las propiedades textuales, hasta que consiga ser autónomo.

Propiedades termodinámicas de sorción de agua de la pulpa de lulo en polvo con encapsulantes

Dados de umidade de equilíbrio de polpa de lulo em pó (PL) com e sem aditivos - 58% de maltodextrina (MD) ou 58% de goma Arábica (GA) - foram determinados nas temperaturas de 20, 30, 40 e 50 °C, utilizando-se o método estático gravimétrico numa faixa de atividade de água de 0,06 a 0,90. As isotermas apresentaram formato sigmoidal do tipo III e o modelo de Guggenhein-Anderson-de Boer (GAB) ajustou satisfatoriamente os dados experimentais de umidade de equilíbrio em função da atividade de água. A adição de encapsulantes afetou as isotermas de tal maneira que na mesma atividade de água, as amostras PL + GA y PL + MD apresentaram um menor conteúdo de umidade de equilíbrio e não foram afetadas pela variação de temperatura. Os calores isostéricos de sorção das polpas em pó com encapsulantes foram maiores (menos negativos) em relação à polpa de lulo em pó, sugerindo a existência de sítios polares mais ativos no produto sem adição de GA ou MD. Uma relação exponencial empírica foi utilizada para descrever a dependência do calor de sorção com o conteúdo de umidade do material.

Influencia de la refusion en las propiedades mecanicas y composicion quimica de aleaciones odontologicas

The objective of the study presented in this article was to analyze the influence of remelting of two odontological alloys: Dentorium and Steeldent, on the mechanical properties and on the chemical composition. For the two alloys, samples, containing 10% and 50% new alloy, were subjected to tensile test, micrography and chemical analysis. The alloys presented similar mechanical properties, except for the elongation, which presented higher values for the Dentorium 50% new alloy. This is due to the smaller carbides formed in this sample. The remelting itself seems not to be responsible for these differences, but they are probably due to the lack of a good control of the casting process. The micrography showed a dendritic column matrix, with carbides in the interdentric region and inside dendritic grain. In the chemical composition was observed few elements percentage change.

Estudio de la adición de K+ y LiNbO3 en las propiedades finales del relaxor PMN procesado por mezcla de polvos

PMN ceramic relaxor has been investigated by several researchers and many aspects of this material, like powder morphology, phase decomposition, weight loss during sintering process, densification, between others, still are investigated. PMN powder preparation has been shown more efficient when synthesized by columbite route, however lead addition stage for the PMN powder synthesis remains problematical. Therefore, this work proposes a new association of methodologies, using columbite route and the hydroxide precipitation method. Through use of the powder mixture technique, which permitted to obtain good green and sintered densities, was possible to observe K+ y Li + dopants reduce weight loss in sintering process and change significantly the dielectric properties. Addition of LiNbO3 seeds in conformation stage, which react in a distinct way as a function of the particle size, promotes the formation of differenced grains in the ceramic bulk. Consequently, very different dielectrics properties from conventional PMN ceramic were obtained.

Influencia del TiO2 y Al2O3 sobre las propiedades eléctricas y microestructurales de cerámicas de SnO2 obtenidas por el método Pechini

Tin oxide has wakened up great scientific and technological interest for its potential use in varistors production and as gas sensor. In order to improve the microstructural and electrical properties in SnO varistor ceramics, the influence of differents dopants used, like TiO2 and Al2O3, is under research. The effect of TiO2 and Al2O3 on the properties of Sn-Co-Nb varistor Systems obtained by the Pechini method has been investigated in this work. Characterization of synthesized raw material was performed by X-Ray Diffraction (XRD) and Scanning Electronic Microscopy (SEM). The microstructural and electrical characterization of sintered samples show that the TiO2 favors the grain growth and the Al2O3, contributes to the decrease it, effect that is manifested in the Sn-Co-Nb varistor systems. Breakdown field increase up to 6300V/cm with increasing Al2O3 content and non-linear coefficients with α=22 were obtained.

Efecto del método de secado en las propiedades termodinámicas de pulpa de mora en polvo

Three different types of maltodextrin encapsulated dehydrated blackberry fruit powders were obtained using vibrofluidized bed drying (VF), spray drying (SD), vacuum drying (VD), and freeze drying (FD). Moisture equilibrium data of blackberry pulp powders with 18% maltodextrin were determined at 20, 30, 40, and 50°C using the static gravimetric method for the water activity range of 0.06-0.90. Experimental equilibrium moisture content data versus water activity were fit to the Guggenheim-Anderson-de Boer (GAB) model. Agreement was found between experimental and calculated values. The isosteric heat of sorption of water was determined using the Clausius-Clapeyron equation from the equilibrium data; isosteric heats of sorption were found to increase with increasing temperature and could be adjusted by an exponential relationship. For freeze dried, vibrofluidized, and vacuum dried pulp powder samples, the isosteric heats of sorption were lower (more negative) than those calculated for spray dried samples. The enthalpy-entropy compensation theory was applied to sorption isotherms and plots of ΔH versus ΔS provided the isokinetic temperatures, indicating an enthalpy-controlled sorption process.