La investigación-acción en didáctica de las ciencias: perspectiva desde las revistas españolas de educación

En este artículo se elabora un marco conceptual de la investigación-acción en educación y se ofrece el desarrollo que dicha modalidad de investigación ha tenido en la Didáctica de las Ciencias, a través de la identificación de los artículos publicados en las revistas de educación españolas y del análisis de sus contenidos. Se aporta el perfil personal, social y cognitivo de esta línea de investigación y la incidencia que ha tenido la investigación-acción española en la Didáctica de las Ciencias, en la práctica docente, en la formación del profesorado y en su desarrollo profesional.This article presents a conceptual framework for action research in Education. It also provides a detailed analysis of the development this modality of research has revealed in Science Education. The investigation has been performed through the identification of those articles published in Spanish journals of Education and the subsequent detailed analysis of their contents. The personal, social and cognitive profile of this line of research is also analyzed, as well as the impact it has had in Spanish action research in Science Education, in teaching practice, in teacher training and in the professional achievements of those teachers

Overview of innovations at public libraries in Segovia province to meet the information needs of immigrants

Public libraries are the entrance to a knowledge society with equal access for everyone and are also a suitable place for the social integration of many different groups of immigrants. Therefore, they should create services and initiate programs in response to the requests of the multicultural communities they serve. Segovia’s libraries identified the information needs of immigrants through a series of questionnaires, administered through direct personal interactions with key informants from three distinct but complementary sources: public libraries, educational centres, and immigrant associations. We offer suggestions on innovative and optimal responses to the needs we detected

La investigación-acción en Didáctica de las Matemáticas: teoría y realizaciones

El objeto del presente artículo es conocer el desarrollo de la investigaciónacción en Didáctica de las Matemáticas desde la identificación y el análisis de los artículos publicados en las revistas españolas de educación. Su marco de referencia teórico-metodológico es la agenda bibliométrica y documental identificada en la investigación española propia de aquella disciplina, así como las distintas tradiciones y realizaciones que configuran este enfoque de investigación. Se elabora una base datos con toda la producción documental y se establece el perfil personal, social y cognitivo que conforma esa línea de investigación.The aim of this paper is to show the development of action research in Mathematics Education through the identification and analysis of the articles published in Spanish educational journals. The theoretical and methodological framework for this study is the bibliometric and documentary agenda present in Spanish research in this field, as well as the different traditions and work undertaken that make up this research approach. All documents produced are placed in a data base and the personal, social and cognitive profile of this line of research is established

Agent-based model for the effect of curing temperature on cement hydration

The agent-based model presented here, comprises an algorithm that computes the degree of hydration, the water consumption and the layer thickness of C-S-H gel as functions of time for different temperatures and different w/c ratios. The results are in agreement with reported experimental studies, demonstrating the applicability of the model. As the available experimental results regarding elevated curing temperature are scarce, the model could be recalibrated in the future. Combining the agent-based computational model with TGA analysis, a semiempirical method is achieved to be used for better understanding the microstructure development in ordinary cement pastes and to predict the influence of temperature on the hydration process

Agent-based modelling for cement hydration

The Agent-Based Modelling and simulation (ABM) is a rather new approach for studying complex systems withinteracting autonomous agents that has lately undergone great growth in various fields such as biology, physics, social science, economics and business. Efforts to model and simulate the highly complex cement hydration process have been made over the past 40 years, with the aim of predicting the performance of concrete and designing innovative and enhanced cementitious materials. The ABM presented here - based on previous work - focuses on the early stages of cement hydration by modelling the physical-chemical processes at the particle level. The model considers the cement hydration process as a time and 3D space system, involving multiple diffusing and reacting species of spherical particles. Chemical reactions are simulated by adaptively selecting discrete stochastic simulation for the appropriate reaction, whenever that is necessary. Interactions between particles are also considered. The model has been inspired by reported cellular automata?s approach which provides detailed predictions of cement microstructure at the expense of significant computational difficulty. The ABM approach herein seeks to bring about an optimal balance between accuracy and computational efficiency

Nanoscale Agent Based Modelling for Nanostructure Development of Cement

Most of macroscopic properties of materials are consequences of processes taking place at the nanoscale. Investigation of phenomena at the sub-micro level to improve the performance of construction materials is one of the main applications of Nanotechnology in Construction. The modelling and simulation of nanostructures is then essential to provide a better understanding of the behaviour of construction materials. We present in this paper an agent-based modelling approach in which a set of interacting agents, capable of organizing themselves dynamically and of adapting to the environment, encapsulate the behaviour of the whole system. This new approach is used for studying the nanostructure development of cement, considering that each individual particle develops its own C-S-H shell critical thickness which triggers the agent for shifting the algorithm to next stage. The algorithm results were compared and found in good agreement with reported experimental work

Modelling hydration process of cement nanoparticles by using an agent-based molecular formation algorithm.

This paper presents an agent-based modelling approach for hydration process of Portland cement taking place at the nanoscale. By following a combination of stochastic, deterministic and adaptive rules, cement system is allowed to evolve from an anhydrous separated state to a bond state with enhanced mechanical properties. We consider the two main chemical reactions producing C-HS gel and portlandite, and identify the related anhydrous cement components as two autonomous agents, while water and hydration time are viewed as activator agents. The material representation consists of a geometrical configuration based on a two-dimensional granular fluid, which shows to be suitable when studying nanostructure formation. The resulting agent-based model is tested on a 103μm x 103μm thin film with 20μm thickness containing anhydrous cement. We evaluate the modelling approach after 7 days of hydration from comparison with experimental results, and agreement is good

Relationships between agents for modelling the intermediate stages of cement hydration

Agent-Based modelling is, in many cases, most natural for describing and simulating a system composed of “behavioral” entities. Whether one is attempting to describe the complex process of cement hydration, an agent-based approach makes the model seem closer to reality. Therefore, it is more natural to describe how the calcium silicate phases individually behave during the hydration Chemistry than to come up with the equations that govern the dynamics of the anhydrous constituents. Because the dynamic equations result from the behavior of the calcium silicate phases, the agent-based model will also enable to study aggregate properties. A model based on agents for the cement hydration, also makes it possible to analyse the formation and growing of the C-S-H gel: the main binding agent in hardened cement. Knowing the initial concentration of the anhydrous constituents makes it possible to create virtual agents which represent and behave according with their reactivity. This work describes an algorithm which cores an agentbased approach for modelling the intermediate stages of cement hydration, focusing on the microstructure development and C-S-H gel formation. Theories relating to the mechanism of cement hydration are examined and these are discussed in terms of the agents behavioral. Monte Carlo method is applied to obtain and analyse the algorithm result

An alternative experimental methodology to determine the diagonal cracking resistance of steel-reinforced concrete beams

[EN]An alternative experimental method for predicting the diagonal shear cracking resistance of steel-reinforced concrete beams is developed in this paper. Conventional extensometric strain-gauge rosettes are placed on the lateral surfaces of a set of four beams. As diagonal cracking propagates through the beams, the load-strain curves flatten out at a plateau and the mechanical property under consideration may be determined. The method is applied to four beams cast from pumpable and self-compacting concrete mixes with cement types I and IV containing electric arc furnace slag aggregates. The feasibility of applying standard design code formulas to the concretes containing these aggregates may therefore be studied and compared with other recent research works. Accurate experimental results were obtained with this method without having to interrupt the test for subjective visual appraisals of the test specimen.The authors wish to express their gratitude to: the Spanish Ministry MICINN, AEI and ERDF [RTI2018097079BC31; PID2020113837RBI00; 10.13039/501100011033; FPU17/03374] ; the Junta de Castilla y Leon (Regional Government) and ERDF [UIC231, BU119P17] ; Youth Employment Initiative (JCyL) and ESF [UBU05B_1274] ; and the University of the Basque Country [PPGA20/26] and University of Burgos [SUCONS, Y135.GI] for additional funding. Our thanks also go to the Basque Government research group [IT131419] and likewise to CHRYSO and HORMOR for supplying the materials used in this research