5,625 research outputs found

    Early detection of learning difficulties using the BADyG-E2r Battery during primary education

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    The aim of the present study was to assess the predictive capacity of several of the most relevant cognitive skills in the academic field that were evaluated using Differential and General Skills Battery(BADyG-E2r). Particular attention was focused on the variables that need to be overcome regarding the curricular objectives related to pass/fail grading as evaluated by the teachers in the instrumental disciplines of Mathematics and Language. The psychometric battery was applied to the 3rd year students in primary education (a total of 512 students) at 4 public schools that were randomly selected in the province of Alicante (Spain). A follow-up of their academic evolution was under taken until the end of primary education. The obtained results show that high scores in Verbal Reasoning, Numerical Reasoning, and Verbal Syllogisms positively and significantly predict academic success at the end of primary education in the subjects of Language and Mathematics

    Implicit finite volume simulation of 2D shallow water flows in flexible meshes

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    In this work, an implicit method for solving 2D hyperbolic systems of equations is presented, focusing on the application to the 2D shallow water equations. It is based on the first order Roe''s scheme, in the framework of finite volume methods. A conservative linearization is done for the flux terms, leading to a non-structured matrix for unstructured meshes thus requiring iterative methods for solving the system. The validation is done by comparing numerical and exact solutions in both unsteady and steady cases. In order to test the applicability of the implicit scheme to real world situations, a laboratory scale tsunami simulation is carried out and compared to the experimental data. The implicit schemes have the advantage of the unconditional stability, but a quality loss in the transient solution can appear for high CFL numbers. The properties of the scheme are well suited for the simulation of unsteady shallow water flows over irregular topography using all kind of meshes

    Implicit 2D surface flow models performance assessment: Shallow Water Equations vs. Zero-Inertia Model

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    Zero-Inertia (ZI) models are used in overland flow simulation due to their mathematical simplicity, compared to more complex formulations such as Shallow Water (SW) models. The main hypothesis in ZI models is that the flow is driven by water surface and friction gradients, neglecting local accelerations. On the other hand, SW models are a complete dynamical formulation that provide more information at the cost of a higher level of complexity. In realistic problems, the usually huge number of cells required to ensure accurate spatial representation implies a large amount of computing effort and time. This is particularly true in 2D models. Hence, there is an interest in developing efficient numerical methods. In general terms, numerical schemes used to solve time dependent problems can be classified in two groups, attending to the time evaluation of the unknowns: explicit and implicit methods. Explicit schemes offer the possibility to update the solution at every cell from the known values but are restricted by numerical stability reasons. This can lead to very slow simulations in case of using fine meshes. Implicit schemes avoid this restriction at the cost of generating a system of as many equations as computational cells multiplied by the number of variables to solve. In this work, an implicit finite volume numerical scheme has been used to solve the 2D equations in both ZI and SW models. The scheme is formulated so that both quadrilateral and triangular meshes can be used. A conservative linearization is done for the flux terms, leading to a non-structured matrix for unstructured meshes thus requiring iterative methods for solving the system. A comparison between 2D SW and 2D ZI is done in terms of performance, efficiency and mesh requirements, in which both models benefit of an implicit temporal discretization in steady and nearly-steady situations

    A 2D finite volume simulation tool to enable the assessment of combined hydrological and morphodynamical processes in mountain catchments

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    Nowadays, the great power of modern computers allows to develop computational models able to deal with simulations of several coupled phenomena over detailed complex topography. An efficient and properly calibrated computational model represents a useful tool to provide insight into the catchment dynamics at hydrological and geomorphological levels. In addition, it allows to develop detailed risk management and conservation plans. In this work, we present a coupled surface-groundwater distributed flow model with hydrological (rainfall and infiltration) and geomorphological (suspended and bed load sediment transport) components. The coupled model is applied to well characterized experimental catchments that are used as realistic test cases. The calibration of the water flow model response to rainfall is performed by means of the fitting to experimental outlet hydrographs of the results supplied by a coupled formulation of 2D Shallow Water Equations and 2D Darcy's law for saturated porous media connected via suitable infiltration laws. The calibration of a suspended and bed load model is also addressed by means of the fitting to experimental outlet sedigraphs. The numerical results show a good agreement between numerical and observed hydrographs and sedigraphs, significantly improving previous published simulations. Additionally, the need to repeat the simulations in the calibration processes is no longer an unapproachable problem

    Integración de usabilidad de software a la plataforma de educación virtual de la Universidad APEC, UNAPEC

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    Los usuarios, docentes y alumnos, de la plataforma de educación virtual que tiene la Universidad APEC, UNAPEC, denominada EVA (Entorno Virtual de Aprendizaje) han venido confrontando ciertos inconvenientes en el uso de la plataforma debido a diferentes factores, entre los cuales se encuentran: Pérdida dentro la página en la que se navega, confusión de los elementos de las actividades que muestra el entorno, escaso tiempo de durabilidad en exámenes online, tardanza en el tiempo de respuesta en los entornos del chat y mensajería, incomprensión de actividades que requieren constante capacitación, lentitud en la descarga de archivos, entre otros inconvenientes, lo cual ha conllevado a una mediana y baja aceptación de la plataforma por parte de un número importante de usuarios, que trae como consecuencia la dilación en el propósito de la universidad a largo plazo: virtualización total de un importante número de asignaturas y posteriormente, de carreras. Para resolver estos inconvenientes y lograr a cabalidad el aprovechamiento de todos los recursos que la plataforma brinda, nos hemos abocado al estudio de la participación de los usuarios en dicha plataforma, así como a la evaluación de los planteamientos iniciales realizados por la universidad para la puesta en funcionamiento de la plataforma, lo cual nos permitirá establecer las mejoras que deben integrarse a la misma. Este estudio determinó que se debía implementar la integración de la usabilidad al entorno, con lo cual se obtendría una plataforma meramente amigable a todo tipo de usuario, desde un estudiante de nuevo ingreso hasta un profesor con poca destreza informática. De esa manera, la universidad lograría en poco tiempo implementar, con todas las ventajas que esto significa, la virtualización total de las carreras y asignaturas que se requieran.Beltré y Navarro: adscritos al Decanato de Ingeniería e Informática de la Universidad APEC. Miyar F., adscrita a la Dirección de Investigación e Innovación Educativa de UNAPEC

    Procesos de alteración de las vidrieras medievales. Estudio y tratamientos de protección

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    The anxiety caused by the fast growing decay of historical stained glass windows as a consequence of increasing environmental pollution, encouraged institutions of several countries to sponsor a series of scientific works aimed both to slow down this fast forwarding deterioration and to develop repair and preservation methods. After an initial review of the chemical composition of the stained glass windows and of the differences depending on historical epochs and origins, a discussion about chemical attack mechanisms, degradation processes and formation of superficial crusts opens up. Finally, the methodology used in their cleaning and restoration is briefly exposed and some criteria on the still polemic quest.La inquietud creada por la creciente alteración que, como consecuencia del aumento de la contaminación atmosférica, están sufriendo las vidrieras históricas, ha movido a las instituciones de varios países a patrocinar la realización de una serie de trabajos científicos dirigidos, por una parte, a detener el avance de este deterioro y, por otra, a desarrollar métodos para su restauración y conservación. Tras una revisión inicial sobre la composición química de las vidrieras y sus diferencias según las distintas épocas y lugares de procedencia, se discuten los mecanismos de ataque químico, los procesos de degradación y la formación de costras superficiales. Finalmente se expone brevemente la metodología seguida para su limpieza y restauración y se comentan algunos de los criterios sobre la todavía polémica cuestión de los tratamientos de protección

    Tratamiento de la gonartrosis con osteotomía tibial de penetración y fijación con grapas

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    La osteotomía metafisaria proximal de tibia ha sido utilizada en el tratamiento de 96 gonartrosis con desviación axil en varo (87 casos) o en valgo (nueve casos), con componente de flexo en la mitad de los casos y con cierto grado de laxitud ligamentosa en 1/3 de los casos. Se utilizó un cálculo angular preoperatorio en bipedestación con contraste opaco del eje mecánico de la extremidad y Rx-TV. La osteotomía fue cuneiforme de penetración, se estabilizó con grapas y se aplicó calza de yeso para facilitar el apoyo precoz. Proporcionó un efecto antiálgico en el 94 % de los casos, pero la valoración funcional deja el resultado en 25 % de casos excelentes y 51% de casos buenos. Destacan la necesidad de operar ambas rodillas, la bondad del resultado con independencia del grado de angulación, la compensación de las laxitudes moderadas ya referidas y la repercusión favorable del realineamiento axil sobre la artrosis femoropatelar presente en el 75 % de los casos

    Insuficiencia cardíaca congestiva en la clínica de pequeños animales. Terapéutica práctica moderna II. Inotropos positivos

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    En el presente trabajo revisamos los usos más frecuentes de los digitálicos, pautas de medicación y elección del producto, dosis, intervalos de dosis, formas comerciales y vías de administración más indicados para cada situación y completamos el tratamiento inotrópico con una revisión de catecolaminas sintéticas, bipiridinas y algunos fármacos potencialmente útiles en la práctica diaria.In this paper tbc autors review tbe more frecuents uses of the digitalis glycosides, dosages, how to choose thee best dtug, dosing intervals, comercial forms availablesin Spain and way of administration more indicated for each clinical situation, and we finish with a quick review of the sinthetic sympathomimetics amines and bipyridine compounds

    STRENGTH-VELOCITY RELATIONSHIP OF RESISTED SWIMMING: A REGRESSION ANALYSIS

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    This study explored how external loads affect semi-tethered resisted swimming (STRS). Twenty national competitive swimmers (age: 18.31 ± 1.42 years) participated in an incremental STRS test. Pearson product-moment correlation coefficients between the load and the swimming variables were obtained, and simple linear regression analyses were applied to evaluate the associations. The results showed that less velocity and acceleration were delivered at high loads (p \u3c 0.001). It increased the velocity fluctuation, affecting the swimming patterns adversely. A decrease in the impulse relative to the load pulled is obtained, especially after 20-30% of the maximal load (R2 = 0.724, p \u3c 0.000). Coaches should reconsider using STRS, as little benefits may be obtained in performance
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