Measuring dispersion in the context of ordered qualitative scales

Producción CientíficaThe main purpose of this contribution is to measure the dispersion associated with the different results of a variable when they form a set of linguistic terms obtained after examining different qualities of people, services, etc, ordered, but with a non-homogeneous and non-quantifiable distance between the linguistic terms.Ministerio de Economía, Industria y Competitividad (project ECO2016-77900-P

Strategies for development of media literacy in Primary: Action proposal

La competencia digital desempeña un papel fundamental en la formación de los estudiantes actualmente. Sólo tenemos que considerar que la tecnología es ubicua en la vida de los estudiantes y también en sus rutinas diarias. Las escuelas deben plantearse cómo implementar e integrar en el currículo la tecnología educativa. La alfabetización mediática se refiere al conocimiento y destrezas que el alumnado debe adquirir para poder analizar, evaluar y crear mensajes mediáticos. Este artículo trata sobre alumnado entre 8 y 11 años que no tiene formación multimedia previa, y aprende lo básico sobre la competencia digital, así como el impacto que esa formación tiene en su progreso académico. Dada la edad de la muestra, las destrezas mediáticas trabajadas no han ido más allá de las tecnológicas, aunque algunas habilidades evaluadoras y críticas se han practicado oralmente. Los resultados muestran que los estudiantes han mejorado significativamente sus destrezas básicas y también su conocimiento sobre los media. Sin embargo, no podemos concluir que una formación tan corta y básica impacte su progreso académico.Digital competency plays an essential role in students' training nowadays. We just need to consider that technology is ubiquitous in students' lives and also part of their daily routines. Schools need to address how ICT is going to be implemented and integrated into the curriculum. Media literacy refers to the knowledge and skills individuals are to be achieved in order to analyze, evaluate, or produce media messages. This article is about how 8 to 11 years old students with no previous background, learn the basics on ICT and its impact on their grades. Because of students' age, literacy skills do not go beyond creating media messages, although some critical and evaluative skills were also orally practiced. Results show that students have significantly improved their basic skills and also their knowledge on media. However, we cannot conclude that this type of short in time and basic training impacts their academic grades

Estimation of specific cutting energy in an S235 alloy for multi-directional ultrasonic vibration-assisted machining using the Finite Element Method

The objective of this work is to analyze the influence of the vibration-assisted turning process on the machinability of S235 carbon steel. During the experiments using this vibrational machining process, the vibrational amplitude and frequency of the cutting tool were adjusted to drive the tool tip in an elliptical or linear motion in the feed direction. Furthermore, a finite element analysis was deployed to investigate the mechanical response for different vibration-assisted cutting conditions. The results show how the specific cutting energy and the material’s machinability behave when using different operational cutting parameters, such as vibration frequency and tool tip motion in the x-axis, y-axis, and elliptical (x-y plane) motion. Then, the specific cutting energy and material’s machinability are compared with a conventional turning process, which helps to validate the finite element method (FEM) for the vibration-assisted process. As a result of the operating parameters used, the vibration-assisted machining process leads to a machinability improvement of up to 18% in S235 carbon steel. In particular, higher vibration frequencies were shown to increase the material’s machinability due to the specific cutting energy decrease. Therefore, the finite element method can be used to predict the vibration-assisted cutting and the specific cutting energy, based on predefined cutting parameters.Peer ReviewedPostprint (published version

Transición de la pizarra a la PDI : reflexiones en torno a la experiencia en los centros de Cantabria y Asturias

La presente comunicación es una reflexión sobre algunos aspectos que subyacen a las investigaciones sobre la integración de la pizarra digital en las aulas de los centros de Primaria. Complementan las conclusiones de los distintos informes elaborados sobre las mismas. Las apreciaciones que aquí ofrecemos han surgido a raíz de la observación del desarrollo de los proyectos en los centros participantes en las dos comunidades autónomas indicada

Cibermedios nativos españoles: explorando modelos de rentabilidad

Online media are undergoing a process of change in both production and distribution systems, in the role of audiences, in journalistic practices and in business models. In the case of online media which exclusively operate in the web, with no print of broadcast matrix, economic viability is even more complicated. This paper analyses the business models of three native online media in Spain: Bottup, Periodismohumano and Somos Malasaña. The conclusions outline their strengths and weaknesses, as well as the difficulties for the success of these online initiatives

La vida en tres dimensiones o el espacio biológico bien temperado

The certainty that natural phenomena and processes could be represented in a physical space ruled by Euclidean geometry was a fundamental epistemological assumption of theoretical creation in classical science. The possibility of a mathematical analysis of the continuum ensured an intuitive, pictorial description of mobile trajectories as studied in dynamics, as well as a precise determination of the effects generated within causal relations. These convictions and assumptions had to be reviewed when the Plank action quantum forced the development of a new physics of atomic systems. Consequences, nevertheless, transcended the scope of Physics and extended to all regions of natural science, including Biology, which had to be built under the conceptual coverage of the nascent mechanics. The present work is a reflection on the philosophical problems posed by the encounter of physics of atoms and chemistry of molecule

Equity pricing in the mining sector: evidence from NYSE and LSE

The study examines the Capital Asset Pricing Model (CAPM) for the mining sector using weekly stock returns from 27 companies traded on the New York Stock Exchange (NYSE) or on the London Stock Exchange (LSE) for the period of December 2008 to December 2010. The results support the use of the CAPM for the allocation of risk to companies. Most companies involved in precious metals (particularly gold), which have a beta value less than unity (Table 1), have been actuated as shelter values during the financial crisis. Values of R2 do not shown very explanatory power of fitted models (R2 < 70 %). Estimated coefficients beta are not sufficient to determine the expected returns on securities but the results of the tests conducted on sample data for the period analysed do not appear to clearly reject the CAP

Arcillas cerámicas de Andalucía. VI. Yacimientos terciarios y cuaternarios de la provincia de Huelva. comarcas de Huelva y El Condado

Se estudian veintiséis muestras de arcilla de interés cerámico, procedentes de diversos yacimientos en explotación situados en el Sur de la provincia de Huelva, en las comarcas de El Condado y zona costera. Los materiales proceden de sedimentos terciarios (la mayor parte) y cuaternarios, constituidos por margas de textura arcillo-arenosa o arcillo-limosa y se emplean en la fabricación de ladrillos y tejas en fábricas modernas de gran producción. Los materiales más plásticos se utilizan en alfarería y talleres de cerámica artística en Huelva y Trigueros. Las técnicas empleadas han sido las Siguientes: Análisis químico, capacidad de cambio, análisis térmico ponderal y diferencial, diagramas de difracción de rayos X, examen al microscopio electrónico, análisis mecánico, agua de moldeo, plasticidad (Riecke) , poroSidad, secado a 50ºC. (Diagramas de Bourry) , contracción por calcinación, peso específico y resistencia a la compresión en probetas calcinadas. Se desprende que estas arcillas son de naturaleza fundamentalmente montmorillonítica, con una elevada participación de minerales caoliníticos y micáceos (ilita y micas potásicas). Como minerales secundarios y accesorios contienen cuarzo, geles y feldespatos. Todas las muestras contienen cantidades medias hasta altas de calcita en grano fino, que en ciertos casos es de mayor tamaño y puede llegar a ser perjudicial sin un tratamiento conveniente. Las pruebas tecnológicas indican que se trata de materiales naturales de buenas propiedades cerámicas, de utilidad para la industria de materiales de construcción, y en otros casos para alfarería y cerámica artística. La gran potencia de los yacimientos, su fácil explotación y laboreo, su situación en terreno llano y de buenas comunicaciones y la constancia en la composición química y textura de la materia bruta, hace que los consideremos de interés industrial.Twenty Six samples of clay, interesting from the ceramic viewpoint, from several beds located in the South of the province of Huelva, in the country of El Condado and the coast have been studied. The great majority of materials belong to the Tertiary and Quaternary sediments and are formed by marls of sandy or silty clayed texture. They are used by large modern factories producing bricks and tiles. The more plastic materials are used by pottery and artistic ceramic industries in Huelva and Trigueros. The following techniques have been used: Chemical analysis, base exchange capacity, ponderal thermal analysis, D. T. A., X-ray difraction, electronic microscope, mechanical analysis, moulding water, plasticity (Riecke), porosity, drying shrinkage at 50°C. (Bourry's diagrams) firing shrinkage, specific gravity and crushing strength of fired bodies. It is concluded that these clays are fundamentally of montmorillonitic nature, with, a high proportion of kaolinitic and micaceous minerals (illite and potasic micas). They contain as secondary minerals, quartz gels and feldspars. All the samples contain medium to high quantities of fine grain ed calcite, which, in some casos, may be of larger size, being pernicious without previous treatment. The technological tests suggest that these materials are of good ceramic properties, useful in the building industry and in other cases, for pottery and artistic ceramics. The great depth of these beds, their easy explotation and working, their situation on flat and well communicated land and the constancy of chemical and textural composition of the raw materials make them of industrial interest

Arcillas cerámicas de Andalucía V. Yacimientos de terrenos ígneos y sedimentos primarios de la provincia de Huelva. Comarcas de Sierra Morena y Andévalo

Twenty two samples of clays, interesting from the ceramic viewpoint, from several beds located on the northern and central regions of the province of Huelva, in the country of Sierra Morena and El Andévalo, respectively, have he en studied. The materials belong to outcrops of igneous nature and slate sediments from the Silurian and Carboniferous, and are of highly sandy texture in general. They are used to make bricks and tiles. The materials of higher clay content are used in pottery and artistic ceramic industries, specially those from Aracena and Cortegana. The following techniques have been used: chemical arialysis, base exchange capacity, ponderal thermal analysis D.T.A., X-ray diffraction, electron microscopy, mechanical analysis, moulding water, plasticity (Riecke), porosity, drying shrinkage at 50ºC. (Bourry's diagrams), firing shrinkage, specific gravity and crushing strength in fired bodies. It is concluded that the main components of the materials belonging to the igneous outcrops (granites, porphides, etc.), are fundamentally of kaolinitic nature, with a high proportion of micaceous minerals, free quartz as an accesory mineral and a variable amount of hydrated iron and aluminum oxides. Minerals of 14 A spacings are scarce. Samples from altered slate of Andévalo show distinctly a higher illite content followed by kaolinite and iron and aluminum gels. The presence of montmorillonitic minerals is more obvious. The technological tests suggest) that these raw materials have good ceramic properties, with a high iron content, appropriate for the uses mentioned above. The small extension of these beds prevent the use of these materials by the large ceramic industries.Se estudian veintidós muestras de arcilla de interés cerámico procedentes de diversos yacimientos situados en las regiones norte y centro de la provincia de Huelva, en las comarcas de Sierra Morena y El Andévalo, respectivamente. Los materiales proceden de afloramientos de naturaleza ígnea y sedimentos de pizarras del Silúrico y Carbonífero, de textura fuertemente arenosa en general, y se emplean en la fabricación de ladrillos y tejas. Los materiales más arcillosos se utilizan en alfarerías y talleres de cerámica artística, destacando los de Aracena y Cortegana. Las técnicas empleadas han sido las siguientes: Análisis químico, capacidad de cambio, análisis térmico ponderal y diferencial, diagramas de difracción de rayos X, examen al microscopio electrónico, análisis mecánico, agua de moldeo, plasticidad (Riecke), porosidad, secado a 50ºC (diagramas de Bourry), contracción por calcinación, peso específico y resistencia a la compresión en probetas calcinadas. Se deduce que los materiales procedentes de yacimientos sobre afloramientos ígneos (granito, pórfidos, etc.) son de naturaleza fundamentalmente caolinita, con una alta proporción de minerales micáceos, cuarzo libre como mineral accesorio y un contenido variable en óxidos de hierro y aluminio hidratados. Minerales con espaciados de 14 A apenas son apreciables. Las muestras procedentes de pizarras alteradas de El Andévalo destacan por su mayor contenido en Hita, seguida de caolinita y geles de hierro y aluminio. Se intensifica la presencia de minerales montmorilloníticos. Las pruebas tecnológicas indican que se trata de materiales naturales de buenas propiedades cerámicas, con alto contenido en hierro, aptos para los usos que hemos citado

Influence of starch source in the required hydrolysis time for the production of maltodextrins with different dextrose equivalent

The starches were statistically different (p &lt; 0.05) in their protein, ash, fat, phosphorus, amylose and amylopectin content. The amylose/amylopectin ratios in corn, potato and rice starches were 0.389, 0.282 and 0.220, respectively. The phosphorus content in the same order of starches was: 0.15 ± 0.01; 0.80 ± 0.02 and 0.95 ± 0.02 g/kg, respectively. The chemical composition of the different starches, and specifically its amylose and amylopectin content, its phosphorus content and the way it is bound to the starch molecule, affect the functional properties like the viscosity of gels and the enzymatic hydrolysis rate of these molecules. The rice starch is easily hydrolyzed by the á-amylase enzyme from Aspergillus oryzae and therefore, it required less time to obtain maltodextrin by enzymatic hydrolysis from rice starch compared with those from corn or potato starch. Under saturation conditions of the enzyme, the dextrose equivalent content was proportional to the hydrolysis time, regardless of the starting starch source.Key words: Starch, maltodextrins, dextrose equivalent, amylose, amylopectin