Razonamiento inductivo de 12 alumnos de secundaria en la resolución de un problema matemático

En este trabajo se presenta el resultado obtenido del análisis de un proceso de razonamiento inductivo desarrollado por 12 estudiantes de secundaria en un contexto de resolución de problemas. Se plantea un problema, en el transcurso de una entrevista, que consiste en determinar el número máximo de regiones que se obtienen al trazar rectas sobre un plano. Durante la resolución del problema los estudiantes, y a través del dialogo con el entrevistador, han de explicar y justificar sus decisiones. Centrándonos en el trabajo de Pólya y en otras investigaciones previas relacionadas sobre este tema, se define un sistema de categorías mediante las cuales se organizan los datos para su análisis.

Numerical investigation of a source extraction technique based on an acoustic correction method

An aerodynamic sound source extraction from a general flow field is applied to a number of model problems and to a problem of engineering interest. The extraction technique is based on a variable decomposition, which results to an acoustic correction method, of each of the flow variables into a dominant flow component and a perturbation component. The dominant flow component is obtained with a general-purpose Computational Fluid Dynamics (CFD) code which uses a cell-centred finite volume method to solve the Reynolds-averaged Navier–Stokes equations. The perturbations are calculated from a set of acoustic perturbation equations with source terms extracted from unsteady CFD solutions at each time step via the use of a staggered dispersion-relation-preserving (DRP) finite-difference scheme. Numerical experiments include (1) propagation of a 1-D acoustic pulse without mean flow, (2) propagation of a 2-D acoustic pulse with/without mean flow, (3) reflection of an acoustic pulse from a flat plate with mean flow, and (4) flow-induced noise generated by the an unsteady laminar flow past a 2-D cavity. The computational results demonstrate the accuracy for model problems and illustrate the feasibility for more complex aeroacoustic problems of the source extraction technique.

Research and perspectives on processing instruction

This volume tracks the impact processing instruction has made since its conception. It provides an overview of new research trends on measuring the relative effects of processing instruction. Firstly, the authors explain processing instruction, both its main theoretical underpinnings as well as the guidelines for developing structured input practices. Secondly, they review the empirical research conducted, to date, so that readers have an overview of new research carried out on the effects of processing instruction. The authors finally reflect on the generalizability and limits of the research on processing instruction and offer future directions for processing instruction research.

Effects of magnetic fields on crystal growth

The effects of a constant uniform magnetic field on thermoelectric currents during dendritic solidification were investigated using a two-dimensional enthalpy based numerical model. Using an approximation for three-dimensional unconstricted growth, the resulting Lorentz forces generate a circulating flow influencing the solidification pattern. Under the presence of a strong magnetic field secondary growth on the clockwise side of the primary arm of the dendrite was encouraged, whereas the anticlockwise side is suppressed due to a reduction in local free energy. The preferred direction of growth rotated in the clockwise sense under an anticlockwise flow. The tip velocity is significantly increased compared with growth in stagnant flow. This is due to a small recirculation at the tip of the dendrite; bringing in colder liquid and lowering the concentration of solute.

Using continuous plankton recorder data

The continuous plankton recorder (CPR) survey is the largest multi-decadal plankton monitoring programme in the world. It was initiated in 1931 and by the end of 2004 had counted 207,619 samples and identified 437 phyto- and zooplankton taxa throughout the North Atlantic. CPR data are used extensively by the research community and in recent years have been used increasingly to underpin marine management. Here, we take a critical look at how best to use CPR data. We first describe the CPR itself, CPR sampling, and plankton counting procedures. We discuss the spatial and temporal biases in the Survey, summarise environmental data that have not previously been available, and describe the new data access policy. We supply information essential to using CPR data, including descriptions of each CPR taxonomic entity, the idiosyncrasies associated with counting many of the taxa, the logic behind taxonomic changes in the Survey, the semi-quantitative nature of CPR sampling, and recommendations on choosing the spatial and temporal scale of study. This forms the basis for a broader discussion on how to use CPR data for deriving ecologically meaningful indices based on size, functional groups and biomass that can be used to support research and management. This contribution should be useful for plankton ecologists, modellers and policy makers that actively use CPR data.

The emotional structure of the advertising message in radio

Radio advertising is suffering from a remarkable crisis of creativity as it has yet not found its role in a radio model based on voice locution and information genres. This article suggests the need for implementing a peripheral or heuristic strategy to attract and hold listeners’ attention. Within this framework, the narration and scene representation are proposed as suitable persuasion techniques. The objective is to design a useful conceptual tool for an efficient creative conception of narration at the service of certain commercial strategy. First, the concept of narrative persuasion is grounded according to the possibilities of the sound code. Second, the keys of scene representation and commercial strategy (brand, product, advantage, benefit and target) within the sound message are presented. And third, these keys are articulated in a model. This model is pre-tested by means of analyzing eight different case-radio ads.

The landing of Commander Bayo in Majorca through the letters of journalist Gabriel Fuster Mayans ‘Gafim’

The well-known Majorcan journalist and town councillor in Palma Gabriel Fuster Mayans, alias Gafim, fought in the ranks of the national side during the Spanish Civil War when he was only 23. Using unpublished letters to his bride, the author has been able to retrace his role during the landing of the ship under the command of captain Bayo in August 1936, an exceptional witness from a man who became one of the most distinguished public figures in the Balearic capital.

An Experiment in Helping Foster-Carers Manage Challenging Behaviour

This article takes issue with those who assume that the responsibility for bad outcomes in social work, such as child deaths, is appropriately laid at the feet of individual workers. It examines the philosophical origins of such arguments, some recent applications within social work literature and their appropriateness to the realities of social work practice. The author argues that a morality of social work must recognize the social and organizational context in which it occurs.