3,844 research outputs found

    Carbonation of concrete with construction and demolition waste based recycled aggregates and cement with recycled content

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    Durability is a major concern in concrete (particularly recycled concrete) structures exposed to carbonation-induced corrosion, given the social, economic, environmental and safety implications involved. This article explores carbonation performance in concrete with 25% or 50% mixed recycled construction and demolition waste aggregate, alone or in conjunction with cement containing 25% fired clay construction and demolition waste. Irrespective of cement type, the mean carbonation depth was slightly greater in materials with 25% or 50% recycled aggregate than in concretes with 100% natural aggregate, although the difference was not statistically significant for the 25% replacement ratio. In all the concretes studied, the carbonation coefficient was below the 4 mm/yr0.5 indicative of good quality. Based on the prediction model proposed in Spain’s concrete code, reinforcement passivity was guaranteed in all these types of concrete when exposed to class XC1 to XC4 carbonation environments for substantially longer than their 100 year design service life.This study was funded under research projects BIA 2013-48876-C3-1-R, BIA2013-48876-C3-2-R and BIA2016-76643-C3-1-R awarded by the Ministry of Science and Innovation and grant GR 18122 awarded to the MATERIA Research Group by the Regional Government of Extremadura and the European Regional Development Fund, ERDF. In 2016 University of Extremadura teaching and research personnel benefitted from a mobility grant (MOV15A029) awarded by the Regional Government of Extremadura and in 2018 from a José Castillejo (CAS17/00313) scholarship granted by the Spanish Ministry of Education, Culture and Sport. Philip Van den Heede is since October 2017 a postdoctoral fellow of the Research Foundation—Flanders (FWO) (project number 3E013917) and acknowledges its support.Peer reviewe

    On the application of model-order reduction algorithms

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    Formación para evaluadores técnicos

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    Desde que el 5 de noviembre del año 1999 viera la luz la Ley 38/1999, de Ordenación de la Edificación (en adelante L.O.E.) el sector de la construcción ha experimentado un fortísimo cambio.Parte del mismo se debe al establecimiento de la obligatoriedad para toda edificación destinada a vivienda (con excepción de la auto-promovida), de la contratación de un Seguro de garantía decenal de estabilidad en edificación. Desde ese momento la gran mayoría de las empresas aseguradoras han comenzado a emitir pólizas de garantía decenal, exigiendo para poder formalizar la misma que previamente haya sido realizada una evaluación de los posibles riesgos por una empresa independiente, los denominados Organismos de Control Técnico(O.C.T ́s), en función de la cual la aseguradora pueda baremar y fijar las condiciones de la póliza. Ante estos requerimientos, las empresas dedicadas a las tareas de evaluación de riesgos han de contar con profesionales capacitados, con amplia formación teórica y a la vez suficiente formación práctica. Para facilitar una posible solución al problema, desde la Escuela Universitaria de ArquitecturaTécnica de al Universidad Politécnica de Madrid, se creó un Curso de Especialización con características concretas que pudieran dar respuesta a esta demanda. Sus características concretas, organización y modelo pedagógico se describen en la presente comunicación

    Survey and brain storming studies about machines, constructions, human and environmental risk consideration in the careers of the Universidad Politécnica of Madrid

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    The Universidad Politécnica of Madrid (UPM) includes schools and faculties that were for engineering degrees, architecture and computer science, that are now in a quick EEES Bolonia Plan metamorphosis getting into degrees, masters and doctorate structures. They are focused towards action in machines, constructions, enterprises, that are subjected to machines, human and environment created risks. These are present in actions such as use loads, wind, snow, waves, flows, earthquakes, forces and effects in machines, vehicles behavior, chemical effects, and other environmental factors including effects of crops, cattle and beasts, forests, and varied essential economic and social disturbances. Emphasis is for authors in this session more about risks of natural origin, such as for hail, winds, snow or waves that are not exactly known a priori, but that are often considered with statistical expected distributions giving extreme values for convenient return periods. These distributions are known from measures in time, statistic of extremes and models about hazard scenarios and about responses of man made constructions or devices. In each engineering field theories were built about hazards scenarios and how to cover for important risks. Engineers must get that the systems they handle, such as vehicles, machines, firms or agro lands or forests, obtain production with enough safety for persons and with decent economic results in spite of risks. For that risks must be considered in planning, in realization and in operation, and safety margins must be taken but at a reasonable cost. That is a small level of risks will often remain, due to limitations in costs or because of due to strange hazards, and maybe they will be covered by insurance in cases such as in transport with cars, ships or aircrafts, in agro for hail, or for fire in houses or in forests. These and other decisions about quality, security for men or about business financial risks are sometimes considered with Decision Theories models, using often tools from Statistics or operational Research. The authors have done and are following field surveys about risk consideration in the careers in UPM, making deep analysis of curricula taking into account the new structures of degrees in the EEES Bolonia Plan, and they have considered the risk structures offered by diverse schools of Decision theories. That gives an aspect of the needs and uses, and recommendations about improving in the teaching about risk, that may include special subjects especially oriented for each career, school or faculty, so as to be recommended to be included into the curricula, including an elaboration and presentation format using a multi-criteria decision model

    Association between sleep-disordered breathing and breast cancer aggressiveness

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    Background Sleep-disordered breathing (SDB) has been associated with cancer aggressiveness, but studies focused on specific tumors are lacking. In this pilot study we investigated whether SDB is associated with breast cancer (BC) aggressiveness. Methods 83 consecutive women <65 years diagnosed with primary BC underwent a home respiratory polygraphy. Markers of SDB severity included the apnea-hypopnea index (AHI) and the 4% oxygen desaturation index (ODI4). The Ki67 proliferation index, lack of hormone receptors (HR-), Nottingham Histological Grade (NHG), and tumor stage were used as markers of BC aggressiveness. The association between SDB and molecular subtypes of BC was also assessed. Results The mean (SD) age was 48.8 (8.8) years and body mass index was 27.4 (5.4) Kg/m2. 42 women (50.6%) were post-menopausal. The median (IQR) AHI was 5.1 (2–9.4), and ODI4 was 1.5 (0.5–5.8). The median (IQR) AHI did not differ between the groups with Ki67>28% and Ki6728% and Ki67<29% (51.2% vs 52.3%, p = 0.90), HR- and HR+ (58.3% vs 49.1%, p = 0.47), NHG categories (p = 0.89), different tumor stages (p = 0.71), or molecular subtypes (p = 0.73). These results did not change when the ODI4 was used instead of the AHI. Conclusion Our results do not support an association between the presence or severity of SDB and BC aggressiveness.Asociación de Neumología y Cirugía Torácica del Sur (NEUMOSUR) 1/201

    Framework for Development Triages through Mobile Applications

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    The emergency triage is being implemented due to the congestion of the emergency services, for several reasons, such as: easy access to the patient, demanding an immediate diagnostic an medical aid, prioritizing severely ill patients rather than patients with minor problems that make improper use of the emergency areas. The objective is building a system, integrated to the main system of health organization, for management of emergency triage. To do this, we have analysed and developed a system which allows us to evaluate patients through a mobile application. Results suggest that the integration of emergency triage to mobile application, helps to improve and optimize resource management and decrease the response time. In conclusion, this system optimizes the resources implemented as well as an increase of customer satisfaction
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