Conocimiento actual de los principios fundamentales de la retracción del hormigón

Not availableLa retracción es, con frecuencia, responsable del agrietamiento del hormigón. Este trabajo resume el estado actual de conocimientos en cuanto a los principios que gobiernan el fenómeno de retracción en el hormigón. La tobermorita es el producto principal de los cementos portland hidratados y es, generalmente, la mayor fuente de retracción por secado en el cemento endurecido. Consecuentemente, la explicación de la retracción por secado se basa en la estructura cristalográfica de la tobermorita, en la naturaleza del agua asociada con ella y en los cambios de volumen que corresponden con los cambios de agua asociada. También se discute brevemente la influencia de otros factores, tales como la composición del cemento, el contenido de árido, la proporción de mezcla y las condiciones de curado

Improving Students’ Social Participation in Primary and Secondary Schools Across Europe

This handbook is the product of collaboration within the “FRIEND-SHIP—Improving Students’ Social Participation in Primary and Secondary Schools Across Europe” Project, funded by the European Commission—Erasmus+ Programme, Project No.: 2019-1-AT01-KA201-05 1226. One of the main outputs of this Project consisted of the development of the FRIEND-SHIP Program, a school-based intervention aimed at improving social participation of all students between 8 and 11 years of age. The FRIEND-SHIP Program is intended to be implemented by teachers and consists of 12 sessions, each with the duration of 45–60 minutes, implemented twice a week over six weeks. The activities that comprise this program are essentially experiential. Students are invited to take an active and involved role by participating in group activities, role-playing, social stories, arts, and physical activities. The main purpose of this handbook is to support teachers in implementing the FRIEND-SHIP program with their classes. This handbook is divided in three parts: • CHAPTERS 1, 2 and 3 cover background information about social participation and inclusion, as well as the description of the target audience of this handbook and the digital tool for evaluating the FRIEND-SHIP Program effects. • CHAPTER 4 covers the FRIEND-SHIP Intervention Program, including guiding principles, aims, and detailed descriptions of sessions. • CHAPTER 5 covers the information gathered with the implementation of the FRIEND-SHIP Intervention Program throughout the Project life.This handbook is the product of collaboration within the “FRIEND-SHIP—Improving Students’ Social Participation in Primary and Secondary Schools Across Europe” Project, funded by the European Commission—Erasmus+ Programme, Project No.: 2019-1-AT01-KA201-05 1226.info:eu-repo/semantics/publishedVersio

Improving Students’ Social Participation in Primary and Secondary Schools Across Europe

INTRODUÇÃO Este manual é o produto da colaboração desenvolvida no âmbito do projeto "FRIEND-SHIP – Improving Students’ Social Participation in Primary and Secondary Schools across Europe", financiado pela Comissão Europeia – Programa Erasmus+, Referência: 2019-1-AT01-KA201-05 1226. Um dos principais resultados deste projeto consistiu no desenvolvimento do Programa FRIEND-SHIP, uma intervenção escolar cujo objetivo é aumentar a participação social de todos os alunos entre os 8 e os 11 anos. O Programa FRIEND-SHIP destina-se a ser implementado por professores e consiste em 12 sessões, cada uma com a duração de 45-60 minutos, implementadas duas vezes por semana, ao longo de seis semanas. As atividades que compõem este programa são essencialmente experimentais. Os alunos são convidados a envolverem-se e a assumirem um papel ativo, participando em atividades de grupo, dramatizações, histórias sociais, atividades físicas e atividades relacionadas com as artes. O principal objetivo deste manual é apoiar os professores na implementação do Programa FRIEND-SHIP com as suas turmas.Projeto financiado pela Comissão Europeia – Programa Erasmus+, Referência: 2019-1-AT01-KA201-05 1226info:eu-repo/semantics/publishedVersio

Search for large missing transverse momentum in association with one top-quark in proton-proton collisions at √s = 13 TeV with the ATLAS detector

This paper describes a search for events with one top-quark and large missing transverse momentum in the final state. Data collected during 2015 and 2016 by the ATLAS experiment from 13 TeV proton–proton collisions at the LHC corresponding to an integrated luminosity of 36.1 fb−1 are used. Two channels are considered, depending on the leptonic or the hadronic decays of the W boson from the top quark. The obtained results are interpreted in the context of simplified models for dark-matter production and for the single production of a vector-like T quark. In the absence of significant deviations from the Standard Model background expectation, 95% confidence-level upper limits on the corresponding production cross-sections are obtained and these limits are translated into constraints on the parameter space of the models considered

Search for large missing transverse momentum in association with one top-quark in proton-proton collisions at s√=13 TeV with the ATLAS detector

This paper describes a search for events with one top-quark and large missing transverse momentum in the final state. Data collected during 2015 and 2016 by the ATLAS experiment from 13 TeV proton–proton collisions at the LHC corresponding to an integrated luminosity of 36.1 fb−1 are used. Two channels are considered, depending on the leptonic or the hadronic decays of the W boson from the top quark. The obtained results are interpreted in the context of simplified models for dark-matter production and for the single production of a vector-like T quark. In the absence of significant deviations from the Standard Model background expectation, 95% confidence-level upper limits on the corresponding production cross-sections are obtained and these limits are translated into constraints on the parameter space of the models considered

“With a little help from my best friend…” : Exploring the social functioning of students with moderate learning difficulties in inclusive educational settings

This study explores the perceived impact of a high-quality best friendship on the social functioning of 20 socially neglected students with moderate learning difficulties (MLD) attending regular secondary schools and on 20 of their typically developing (TD) classmates of a similar social status. The analysis of the data from the semi-structured interviews conducted indicates that all participating students had managed to establish one close friendship and held positive perceptions about its quality. However, students with MLD expressed more reserved views about some aspects of their best friendship compared to their TD peers. The paper concludes with highlighting the need for schools to actively support socially neglected students to establish close relations and transcend their marginalization. © 2020 Elsevier Lt

Social Participation and Quality of Best Friendship of Students With Moderate Learning Difficulties in Early Adolescence: A Longitudinal Study

Recent sociometric research has described students with special educational needs (SEN) as less accepted and experiencing more social difficulties than their classmates without SEN. This study addresses the social participation of students with moderate learning difficulties (MLD) in regular schools while also focusing on the quality of their best friendship. In this longitudinal study, 313 secondary students, including 46 with MLD, were first examined while at Grade 7 (T1) and 2 years later at Grade 9 (T2). In line with previous studies, the students with MLD held reduced peer acceptance, had fewer friendships, and engaged less often in social interactions with peers than their typically developing classmates on both administrations. However, students with MLD held positive perceptions of social self-concept and friendship quality, with the two measures being positively associated. At T2, students with MLD reported poorer socio-emotional skills, which were positively correlated with their perceptions of both social self-concept and friendship quality. The paper concludes by outlining the importance of supporting students’ socio-emotional development through implementing relevant school-based interventions. © The Author(s), 2022. Published by Cambridge University Press

Influence de la solvatation preferentielle sur les dimensions des polymeres en solution dans des melanges de solvants

We have studied the dependence of the intrinsic viscosity number of polymers on the composition of binary solvents. The systems studied are: polystyrene in CCl4/CH3OH, C6H6/CH3OH and C6H6/heptane and poly-2-vinylpyridine in CHCl3/CH3CH2OH. We have also studied, for the same systems, preferential solvation of the polymers, using light scattering. We have observed that, near the θ point, short polystyrene chains exhibit a higher expansion than long chains. This was explained in terms of the dependence of preferential solvation on molecular weight. For the system poly-2-vinylpyridine/CH3CH2OH/CHCl3, we have established the viscosity increment dependence on solvent composition. The curve describing this increment differs markedly from the theoretical curve based on GE values (excess free energy) of the solvent mixture. However, taking into consideration the process of preferential solvation, the experimental curve can be corrected and becomes very similar in shape to the theoretical curve but there still remains a quantitative difference between the two curves. © 1973