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

Mean Reversion of the Real Exchange Rate and the validity of PPP Hypothesis in the context of Bangladesh: A Holistic Approach

The real bilateral exchange rates in many countries have recently been found to be non-stationary in nature implying that they do not tend to revert to a long-run mean. Such empirical findings of real exchange rate being non-stationary in the long-run have thrown the well-known, yet now controversial, theory of Purchasing Power Parity (PPP) under fire. This paper aims to add to the few research works on the validity of PPP hypothesis in case of real exchange rate of Bangladesh by undertaking various approaches. We used five important real exchange rates for Bangladesh with its five important partners of international trade. For validating the PPP hypothesis the stationarity of these real exchange rates have been diagnosed. The tests range from the very rudimentary Augmented Dickey Fuller (ADF) and Phillips Perron tests and other univariate unit root tests, to the tests which addresses one/more breaks in the time series data and finally panel unit root tests that account for the possible presence of cross-sectional dependence in dataset. Such a thorough approach was taken to access the issue of the presence of unit root in real exchange rate in every way feasible, assuming the adjustment process is linear. Almost all the results corroborated each others’ conclusions that the real bilateral exchange rates of Bangladesh with five of its major trading partners are in fact not mean-reverting in the long run and so PPP hypothesis does not hold. Therefore, caution must be practiced when making policies for the country where the stipulated PPP hypothesis is assumed to be accurate

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

Modified Polymeric Biosorbents from Rumex acetosella for the Removal of Heavy Metals in Wastewater

The contamination of water resources by effluents from various industries often contains heavy metals, which cause irreversible damage to the environment and health. The objective was to evaluate different biosorbents from the weed Rumex acetosella to remove metal cations in wastewater. Drying, grinding and sieving of the stems was carried out to obtain the biomass, re taining the fractions of 250 to 500 µm and 500 to 750 µm, which served to obtain the biosorbents in natura (unmodified), acidic, alkaline, and mixed. Proximal analysis, PZC, TOC, removal capacity, influence of pH, functional groups, thermal analysis, structural characteristics, adsorption iso therms, and kinetic study were evaluated. The 250 µm mixed treatment was the one that presented the highest removal percentages, mainly due to the OH, NH, -C-H, COOH, and C-O functional groups achieving the removal of up to 96.14% of lead, 36.30% of zinc, 34.10% of cadmium and 32.50% of arsenic. For contact times of 120 min and an optimum pH of 5.0, a loss of cellulose mass of 59% at 328 °C and a change in the surface of the material were also observed, which allowed for obtaining a topography with greater chelating capacity, and the Langmuir and pseudo-second or der models were better fitted to the adsorption data. The new biosorbents could be used in wastewater treatment economically and efficiently

Microencapsulation of Erythrocytes Extracted from Cavia porcellus Blood in Matrices of Tara Gum and Native Potato Starch

Ferropenic anemy is the leading iron deficiency disease in the world. The aim was to encapsulate erythrocytes extracted from the blood of Cavia porcellus, in matrices of tara gum and native potato starch. For microencapsulation, solutions were prepared with 20% erythrocytes; and encapsulants at 5, 10, and 20%. The mixtures were spray-dried at 120 and 140 ◦C. The iron content in the erythrocytes was 3.30 mg/g and between 2.32 and 2.05 mg/g for the encapsulates (p < 0.05). The yield of the treatments varied between 47.84 and 58.73%. The moisture, water activity, and bulk density were influenced by the temperature and proportion of encapsulants. The total organic carbon in the atomized samples was around 14%. The particles had diverse reddish tonalities, which were heterogeneous in their form and size; openings on their surface were also observed by SEM. The particle size was at the nanometer level, and the zeta potential (ζ) indicated a tendency to agglomerate and precipitation the solutions. The presence of iron was observed on the surface of the atomized by SEM-EDX, and FTIR confirmed the encapsulation due to the presence of the chemical groups OH, C-O, C-H, and N-H in the atomized. On the other hand, high percentages of iron release in vitro were obtained between 88.45 and 94.71%. The treatment with the lowest proportion of encapsulants performed at 140 ◦C obtained the best results and could potentially be used to fortify different functional foods

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