Treatment of end-of-life concrete in an innovative heating-air classification system for circular cement-based products

A stronger commitment towards Green Building and circular economy, in response to environmental concerns and economic trends, is evident in modern industrial cement and concrete production processes. The critical demand for an overall reduction in the environmental impact of the construction sector can be met through the consumption of high-grade supplementary raw materials. Advanced solutions are under development in current research activities that will be capable of up-cycling larger quantities of valuable raw materials from the fine fractions of End-of-Life (EoL) concrete waste. New technology, in particular the Heating-Air classification System (HAS), simultaneously applies a combination of heating and separation processes within a fluidized bed-like chamber under controlled temperatures (±600 °C) and treatment times (25–40 s). In that process, moisture and contaminants are removed from the EoL fine concrete aggregates (0–4 mm), yielding improved fine fractions, and ultrafine recycled concrete particles (<0.125 mm), consisting mainly of hydrated cement, thereby adding value to finer EoL concrete fractions. In this study, two types of ultrafine recycled concrete (either siliceous or limestone EoL concrete waste) are treated in a pilot HAS technology for their conversion into Supplementary Cementitious Material (SCM). The physico-chemical effect of the ultrafine recycled concrete particles and their potential use as SCM in new cement-based products is assessed by employing substitutions of up to 10% of the conventional binder. The environmental viability of their use as SCM is then evaluated in a Life Cycle Assessment (LCA). The results demonstrated accelerated hydration kinetics of the mortars that incorporated these SCMs at early ages and higher mechanical strengths at all curing ages. Optimal substitutions were established at 5%. The results suggested that the overall environmental impact could be reduced by up to 5% when employing the ultrafine recycled concrete particles as SCM in circular cement-based products, reducing greenhouse gas emissions by as much as 41 kg CO2 eq./ton of cement (i.e. 80 million tons CO2 eq./year). Finally, the environmental impacts were reduced even further by running the HAS on biofuel rather than fossil fuel.The authors of the present paper, prepared in the framework ofthe Project VEEP "Cost-Effective Recycling of C&DW in High AddedValue Energy Efficient Prefabricated Concrete Components forMassive Retrofitting of our Built Environment", wish to acknowl-edge the European Commission for its support. This project hasreceived funding from the European Union’s Horizon 2020 researchand innovation programme under grant agreement No 723582.This paper reflects only the author’s view and the European Com-mission is not responsible for any use that may be made of theinformation it contains.The authors are also grateful to the Spanish Ministry of Science,Innovation and Universities (MICIU) and the European RegionalDevelopment Fund (FEDER) for funding this line of research(RTI2018-097074-B-C21)

Um modelo para armar: Uma proposta metodológica para abordar o estudo comparativo da história da saúde pública, das profissões da saúde e de suas relações de via dupla com a sociedade

Objetivo. El artículo presenta la propuesta teórico-metodológica que, a partir de elementos ya trabajados previamente, se construyó durante la primera fase de un proyecto de largo alcance que busca elaborar una historia comparada de la medicina y la salud pública en América Latina. Metodología. Para exponer dicha propuesta, en un primer momento se elabora un breve balance historiográfico de la literatura existente sobre la historia de la medicina y de la salud pública en América Latina; en un segundo momento, se plantea una reconfiguración del concepto de ‘campo de la salud’, basada en un análisis crítico del concepto, y que se va perfilando como el marco de referencia para un programa de investigación en estudios sociales de la salud de largo plazo, en la Universidad del Rosario, programa en el cual se enmarca este proyecto comparativo; y, en un tercer momento, se presentan los lineamientos generales de la propuesta sobre la que se sustentará el Proyecto. Resultados: Como resultado final se presenta una matriz que se estructuró a partir de todos los elementos teórico metodológicos articulados en este estudio historiográfico. Dicha matriz está compuesta de nueve atributos y sus correspondientes categorías, que se utilizarán para llevar a cabo la segunda fase del proyecto comparativo de la historia de la medicina y la salud pública. La matriz se usará tanto para guiar la búsqueda de la información histórica como para llevar a cabo el análisis y la comparación.Objetivo. O artigo apresenta a proposta teórico-metodológica que, a partir de elementos já trabalhados previamente, se construiu durante a primeira fase de um projeto de longo alcance que busca elaborar uma história comparada da medicina e a saúde pública na América Latina. Metodologia. Para expor dita proposta, em um primeiro momento elabora-se um breve balanço historiográfico da literatura existente sobre a história da medicina e da saúde pública na América Latina;em um segundo momento expõe-se uma reconfiguração do conceito de “campo da saúde”, baseada em uma análise crítica do conceito, e que vai-se perfilando como o marco de referencia para um Programa de Pesquisa em Estudos Sociais da Saúde de longo prazo, na Universidad del Rosario, programa no qual moldura-se este Projeto Comparativo; e em um terceiro momento, se apresentam os lineamentos gerais da proposta sobre a que se sustentará o Projeto. Resultados. Como resultado final apresenta-se uma matriz que se estruturou a partir de todos os elementos teórico-metodológicos articulados neste estudo historiográfico. Dita matriz está composta de nove atributos e suas categorias correspondentes, que se utilizarão para levar a cabo a segunda fase do projeto comparativo da história da medicina e a saúde pública. A matriz se usará tanto para guiar a busca da informação histórica quanto para levar a cabo a análise e a comparaçãoThe article shows the theoretical and methodological proposal that, grounded in previous studies, was built during the first phase of a long-term project that seeks to develop a comparative history of medicine and public health in Latin America. For laying out purposes, this article initially develops a brief historiographical overview of the literature on the history of medicine and public health in Latin America. It then proposes a reconfiguration of the ‘health field’ concept, based on a critical analysis of the concept, that begins to appear as a framework for a long term program of Social Studies of Health Research in El Rosario University, in which this comparative proposal is articulated. In a third moment, the article presents the general outlines of the proposal. As a final result, it presents a matrix to be used in the second phase of the comparative project of the history of medicine and public health in Latin America. It was structured upon all the theoretical and methodological elements discussed in this historiography study. This matrix was composed by nine attributes and their corresponding categories, which will be used as a guide to gather the historical records and to do the respective analysis and comparison

Temperature dependence of the magnetic properties in LaMnO_(3+δ)

Data are presented on the thermal dependence of the hysteretic properties of cationic vacancies including manganite samples of composition LaMnO_(3+δ)(δ=0.05 and 0.12). Our results evidence the presence in both samples of two magnetic phases having ferro- and antiferromagnetic orders, respectively. The temperature dependence of the coercivity and relaxational properties of the samples is closely linked to the connectivity of the magnetic moment bearing Mn^(3+)-Mn^(4+) ferromagnetic clusters that demagnetize independently in the case of the δ=0.05 sample and collectively in that of the δ=0.12 one, as evidenced from the activation volume results (delta=0.05) which yielded a size of the same order magnitude as that obtained in previous works for the Mn^(3+)-Mn^(4+) ferromagnetic cluster size

On paraquaternionic submersions between paraquaternionic K\"ahler manifolds

In this paper we deal with some properties of a class of semi-Riemannian submersions between manifolds endowed with paraquaternionic structures, proving a result of non-existence of paraquaternionic submersions between paraquaternionic K\"ahler non locally hyper paraK\"ahler manifolds. Then we examine, as an example, the canonical projection of the tangent bundle, endowed with the Sasaki metric, of an almost paraquaternionic Hermitian manifold.Comment: 13 pages, no figure

Calidad relacional de las mujeres rurales en las redes sociales on line: validación del constructo con PLS (Partial Least Squares)

El objetivo de esta investigación es la validación del constructo“calidad relacional percibida” por mujeres de zonas rurales en las redes sociales online. Para ello, abordamos la medida de la calidad relacional percibidaincorporando una nueva dimensión: las interacciones de regulación, a las consideradas en estudios previos como la confianza, la satisfacción y el compromiso. El diseño correlacional se basa en un estudio tipo survey apoyado en entrevistas personales a 478 mujeres de la provincia de Sevilla. Las respuestas se recogen en escalas tipo Likert (0-4). El análisis de datos combina técnicas exploratorias y confirmatorias usando SPSS (v. 18) y SmartPLS 2.0. Obtenemos un modelo de ecuaciones estructurales que confirma las hipótesis de relaciones entre las dimensiones establecidas, con altos indicadores de fiabilidad y validez. Los resultados obtenidos nos permiten planificar y tomar decisiones que inciden en una mejora de sus interacciones en las redes sociales online.The focus of our research is the perceived relationship quality by women. Within this, we try to solve a problem of measuring the quality of the relationship, while we hope to link a new dimension to the measurement process. This is a correlational study, based on interviews "face to face". Their responses are recorded using Likert scales (0-4). There have been 478 women interviewed of the province of Seville. For data analysis we used SPSS and also combine exploratory and confirmatory analytical techniques, using SmartPLS 2.0.As the study results we obtain a structural equation model confirms the hypothetical set of relationships between the 4 dimensions. Also, we obtained high indicators of reliability and validity for the measurement model. The results obtained allow us to develop plans and make decisions on how to support women in rural areas to conduct a more profitable use of their interactions in social networks

Measurement of fragmentation cross sections of 12C ions on a thin gold target with the FIRST apparatus

A detailed knowledge of the light ions interaction processes with matter is of great interest in basic and applied physics. As an example, particle therapy and space radioprotection require highly accurate fragmentation cross-section measurements to develop shielding materials and estimate acute and late health risks for manned missions in space and for treatment planning in particle therapy. The Fragmentation of Ions Relevant for Space and Therapy experiment at the Helmholtz Center for Heavy Ion research (GSI) was designed and built by an international collaboration from France, Germany, Italy, and Spain for studying the collisions of a 12C ion beam with thin targets. The collaboration’s main purpose is to provide the double-differential cross-section measurement of carbon-ion fragmentation at energies that are relevant for both tumor therapy and space radiation protection applications. Fragmentation cross sections of light ions impinging on a wide range of thin targets are also essential to validate the nuclear models implemented inMC simulations that, in such an energy range, fail to reproduce the data with the required accuracy. This paper presents the single differential carbon-ion fragmentation cross sections on a thin gold target, measured as a function of the fragment angle and kinetic energy in the forward angular region (θ 6◦), aiming to provide useful data for the benchmarking of the simulation softwares used in light ions fragmentation applications. The 12C ions used in the measurement were accelerated at the energy of 400 MeV/nucleon by the SIS (heavy ion synchrotron) GSI facility.Comunidad Europea FP7 PITNGA-2008-215840-PARTNERJunta de Andalucía y Ministerio de Ciencia e Innovación P07-FQM-02894 FIS2008-04189 FPA2008- 04972-C0

Higher-order Mechanics: Variational Principles and other topics

After reviewing the Lagrangian-Hamiltonian unified formalism (i.e, the Skinner-Rusk formalism) for higher-order (non-autonomous) dynamical systems, we state a unified geometrical version of the Variational Principles which allows us to derive the Lagrangian and Hamiltonian equations for these kinds of systems. Then, the standard Lagrangian and Hamiltonian formulations of these principles and the corresponding dynamical equations are recovered from this unified framework.Comment: New version of the paper "Variational principles for higher-order dynamical systems", which was presented in the "III Iberoamerican Meeting on Geometry, Mechanics and Control" (Salamanca, 2012). The title is changed. A detailed review is added. Sections containing results about variational principles are enlarged with additional comments, diagrams and summarizing results. Bibliography is update

Investigaciones recientes sobre el langostino nativo Macrobrachium americanum (Decapoda: Palaemonidae) con fines de acuicultura y conservación

where good management practices on aquaculture are mandatory. The economic and ecological importance of prawns of the Genus Macrobrachium cause an impact at a global level involving economic, academic and social aspects. Macrobrachium americanum appears as one of the genus species with high nutritional value and an economic demand in the national and international markets, as well as a vital income for fisherman and producers of this species. For researchers, it is a challenge to find solutions to culture and propose conservation measures for M. americanum with emphasis on development, nutrition and reproduction. Although there are scientific studies supporting the economic importance of this species, our knowledge about its cultivation, reproduction and conservation is limited. This paper summarizes the latest studies made in cooperation with M. americanum in research lead by the Centro de Investigaciones Biológicas del Noroeste, Mexico. After several years of continuous research, it is considered that those efforts have produced useful information for the sustainable exploitation, conservation and basic management practices of this species.En los últimos tiempos ha existido una gran preocupación por la conservación y uso adecuados de los recursos naturales vivos, donde las buenas prácticas de manejo en la acuicultura son importantes. La importancia económica y pesquera de los langostinos del Género Macrobrachium causa un impacto a nivel global que incluye aspectos económicos, académicos y sociales. Macrobrachium americanum se presenta como una de las especies del género con alto valor nutritivo y demanda económica en el mercado nacional e internacional y constituye un importante ingreso para los pescadores y productores de esta especie. Para los investigadores es un desafío encontrar soluciones para la conservación del M. americanum con énfasis en el desarrollo, la nutrición y la reproducción. Aunque existen estudios científicos que avalan la importancia económica de esta especie, nuestro conocimiento sobre su cultivo, reproducción y conservación es limitado. Este artículo resume algunos estudios en colaboración sobre M. americanum, liderados por el Centro de Investigaciones Biológicas del Noroeste, México. Después de varios años de investigación continua, se considera que esos esfuerzos han producido información útil para la explotación sostenible, conservación y las posibles medidas de manejo para esta especie

Aportaciones al conocimiento de la evolución paleoclimática y paleoambiental en la Península Ibérica durante los dos ultimos millones de años a partir del estudio de trasvertinos y espeleotemas

En este trabajo se contemplan los resultados principales del Proyecto" Reconstrucción Paleoclimática desde el Pleistoceno Medio a partir de análisis geocronológicos e isotópicos de travertinos españoles" (P. CEC FI2W-CT91-0075 " Paleoclimatological revision of climate evolution in the Western Mediterranean Region, Evaluation of altered scenarios) . Se seleccionaron cuatro áreas de depósitos travertínicos de carácter fluvial (Priego, Río Blanco), lacustre (Río Blanco, Banyoles) y aluvial (Tolox) así como una zona con depósitos espeleotémicos (Karst de la Cueva del Reguerillo). En ellas se obtuvieron datos sobre la evolución del paisaje y del clima, los travertinos y espeleotemas son indicadores de clima cálido s.l. que de forma abreviada son: O Mediante la geomorfología y dataciones (paleomagnetismo, U/Th, Resonancia de espín Resumen electrónico y racemización de aminoácidos), se determinó las historia fluvial de los travertinos de Priego y Río Blanco así como del Karst de la Cueva del Reguerillo donde, además, se dataron un paleosismo y fenómenos de neotectónica. La data más antigua obtenida mediante Resonancia de espín electrónico fue 950ka, mientras que mediante racemización de aminoácidos se dataron depósitos de más de 750ka. Mediante dataciones, sedimentología, análisis de isótopos estables y palinología se determinaron aspectos de la evolución climática de algunas áreas de la Península Ibérica. La correlación entre palinología e isotopía permitió la validación de algunos de los resultados. También se obtuvieron datos cualitativos sobre input hidraúlicos a los sistemas fluviales o kársticos