148 research outputs found

    Gender Norms and Other Factors Explaining the Gender Gap in Students’ Entrepreneurial Inclination in Spain and Iceland

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    Young women still have a lower entrepreneurial inclination (EI) than young men in both a Latin society (Spain) and in a Nordic society (Iceland). Our data come from a survey conducted among university students who attended the Complutense University of Madrid and the University of Iceland. After constructing a set of variables and indicators that served as explanatory variables, and after conducting a statistical and regression analysis, this study provides evidence about the determinants of this gender gap in EI. The EI of male students was more sensitive to having higher self-confidence than in the case of female students. In turn, the EI of female students was more sensitive to both positive (enrichment) and negative (conflict) perspectives about the work–family interface than in the case of males. Additionally, the EI of students was positively related with entrepreneurial family antecedents, and with the level of parental income; and it was negatively related with their tolerance for risk. Some cross-cultural differences were also found between the Spanish and Icelandic samples

    Can an egalitarian reform in the parental leave system reduce the motherhood labor penalty? Some evidence from Spain

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    The article analyzes how an egalitarian reform in the parental leave system may reduce the motherhood penalty. We used a sample of heterosexual dual-earner couples, with children between 3-8 years old, residing in Madrid and its metropolitan area. We show, first, that the introduction of a 13-day paternity leave increased significantly the average number of days that employed fathers were off work after the birth or adoption of a child. Second, we found some empirical evidence that fathers who took longer leaves tended to be subsequently more involved in the care of their children. And third, we obtained some evidence in favor of the hypotheses that when the father is actively involved in the care of his child the mother tends to experience less work penalty. We also considered the effect of other variables such as having egalitarian gender attitudes, working in a family-friendly company, earnings and the working week

    Effect of Design Parameters on Compressive and Split Tensile Strength of Self-Compacting Concrete with Recycled Aggregate: An Overview

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    [EN] One of the prime objectives of this review is to understand the role of design parameters on the mechanical properties (Compressive and split tensile strength) of Self-Compacting Concrete (SCC) with recycled aggregates (Recycled Coarse Aggregates (RCA) and Recycled Fine Aggregates (RFA)). The design parameters considered for review are Water to Cement (W/C) ratio, Water to Binder (W/B) ratio, Total Aggregates to Cement (TA/C) ratio, Fine Aggregate to Coarse Aggregate (FA/CA) ratio, Water to Solid (W/S) ratio in percentage, superplasticizer (SP) content (kg/cu.m), replacement percentage of RCA, and replacement percentage of RFA. It is observed that with respect to different grades of SCC, designed parameters affect the mechanical properties of SCC with recycled aggregates

    Influence of Design Parameters on Fresh Properties of Self-Compacting Concrete with Recycled Aggregate—A Review

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    [EN] This article presents an overview of the bibliographic picture of the design parameter’s influence on the mix proportion of self-compacting concrete with recycled aggregate. Design parameters like water-cement ratio, water to paste ratio, and percentage of superplasticizers are considered in this review. Standardization and recent research on the usage of recycled aggregates in self-compacting concrete (SCC) exploit its significance in the construction sector. The usage of recycled aggregate not only resolves the negative impacts on the environment but also prevents the usage of natural resources. Furthermore, it is necessary to understand the recycled aggregate property’s role in a mixed design and SCC properties. Design parameters are not only influenced by a mix design but also play a key role in SCC’s fresh properties. Hence, in this overview, properties of SCC ingredients, calculation of design parameters in mix design, the effect of design parameters on fresh concrete properties, and the evolution of fresh concrete properties are studied.S

    Quality Assessment of Mixed and Ceramic Recycled Aggregates from Construction and Demolition Wastes in the Concrete Manufacture According to the Spanish Standard

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    [EN] Construction and demolition waste (CDW) constitutes an increasingly significant problem in society due to the volume generated, rendering sustainable management and disposal problematic. The aim of this study is to identify a possible reuse option in the concrete manufacturing for recycled aggregates with a significant ceramic content: mixed recycled aggregates (MixRA) and ceramic recycled aggregates (CerRA). In order to do so, several tests are conducted in accordance with the Spanish Code on Structural Concrete (EHE-08) to determine the composition in weight and physic-mechanical characteristics (particle size distributions, fine content, sand equivalent, density, water absorption, flakiness index, and resistance to fragmentation) of the samples for the partial inclusion of the recycled aggregates in concrete mixes. The results of these tests clearly support the hypothesis that this type of material may be suitable for such partial replacements if simple pretreatment is carried out. Furthermore, this measure of reuse is in line with European, national, and regional policies on sustainable development, and presents a solution to the environmental problem caused by the generation of CDW

    Influence of the use of External Carbon Fiber Reinforcement on the Flexural Behavior of Prismatic Concrete Test Specimens. An Application for Repairing of Deteriorated Agricultural Structures

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    This manuscript reports a study of the capacity of polymer composites to increase flexural strength in concrete. The polymer composites reinforced with carbon fiber and bonded with epoxy adhesive were used in prismatic test specimens of mass concrete corresponding to two different morphologies. The aim was to simulate the restoration of deteriorating concrete agricultural structures in order to explore the viability of this alternative against replacing them. An increase was found in the strength of the elements tested, with a higher strength being observed in those test specimens presenting a modified geometry.NOThis research was funded by SPANISH MINISTER OF ECONOMY AND COMPETITIVENESS, grant number BIA2017-83526RThe authors acknowledge the technical support and material used for experiments donated by Sika Grou

    Pre-Saturation Technique of the Recycled Aggregates: Solution to the Water Absorption Drawback in the Recycled Concrete Manufacture

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    The replacement of natural aggregates by recycled aggregates in the concrete manufacturing has been spreading worldwide as a recycling method to counteract the large amount of construction and demolition waste. Although legislation in this field is still not well developed, many investigations demonstrate the possibilities of success of this trend given that concrete with satisfactory mechanical and durability properties could be achieved. However, recycled aggregates present a low quality compared to natural aggregates, the water absorption being their main drawback. When used untreated in concrete mix, the recycled aggregate absorb part of the water initially calculated for the cement hydration, which will adversely affect some characteristics of the recycled concrete. This article seeks to demonstrate that the technique of pre-saturation is able to solve the aforementioned problem. In order to do so, the water absorption of the aggregates was tested to determine the necessary period of soaking to bring the recycled aggregates into a state of suitable humidity for their incorporation into the mixture. Moreover, several concrete mixes were made with different replacement percentages of natural aggregate and various periods of pre-saturation. The consistency and compressive strength of the concrete mixes were tested to verify the feasibility of the proposed techS

    Recycling Aggregates for Self-Compacting Concrete Production: A Feasible Option

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    [EN] The use of construction and demolition wastes (C&DW) is a trending future option for the sustainability of construction. In this context, a number of works deal with the use of recycled concrete aggregates to produce concrete for structural and non-structural purposes. Nowadays, an important number of C&DW management plants in the European Union (EU) and other countries have developed robust protocols to obtain high-quality coarse recycled aggregates that comply with different European standards in order to be used to produce new concrete. The development of self-compacting concrete (SCC) is another way to boost the sustainability of construction, due to the important reduction of energy employed. Using recycled aggregates is a relatively recent scientific area, however, studies on this material in the manufacture of self-compacting concrete have proven the feasibility thereof for conventional structural elements as well as high-performance and complex structural elements, densely reinforced structures, difficult-to-access formwork and difficult-to-vibrate elements. This paper presents an original study on the use of coarse recycled concrete aggregate (CRA) to obtain self-compacting concrete. Concrete with substitution ratios of 20%, 50% and 100% are compared with a control concrete. The purpose of this comparison is to check the influence of CRA on fresh SCC as well as its physical and mechanical properties. The parameters studied are material characterization, self-compactability, compressive strength, and tensile and flexural strength of the resulting concrete. The results conclude that it is feasible to use CRA for SCC production with minimal losses in the characteristics

    Muecas: a multi-sensor robotic head for affective human robot interaction and imitation

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    Este artículo presenta una cabeza robótica humanoide multi-sensor para la interacción del robot humano. El diseño de la cabeza robótica, Muecas, se basa en la investigación en curso sobre los mecanismos de percepción e imitación de las expresiones y emociones humanas. Estos mecanismos permiten la interacción directa entre el robot y su compañero humano a través de las diferentes modalidades del lenguaje natural: habla, lenguaje corporal y expresiones faciales. La cabeza robótica tiene 12 grados de libertad, en una configuración de tipo humano, incluyendo ojos, cejas, boca y cuello, y ha sido diseñada y construida totalmente por IADeX (Ingeniería, Automatización y Diseño de Extremadura) y RoboLab. Se proporciona una descripción detallada de su cinemática junto con el diseño de los controladores más complejos. Muecas puede ser controlado directamente por FACS (Sistema de Codificación de Acción Facial), el estándar de facto para reconocimiento y síntesis de expresión facial. Esta característica facilita su uso por parte de plataformas de terceros y fomenta el desarrollo de la imitación y de los sistemas basados en objetivos. Los sistemas de imitación aprenden del usuario, mientras que los basados en objetivos utilizan técnicas de planificación para conducir al usuario hacia un estado final deseado. Para mostrar la flexibilidad y fiabilidad de la cabeza robótica, se presenta una arquitectura de software capaz de detectar, reconocer, clasificar y generar expresiones faciales en tiempo real utilizando FACS. Este sistema se ha implementado utilizando la estructura robótica, RoboComp, que proporciona acceso independiente al hardware a los sensores en la cabeza. Finalmente, se presentan resultados experimentales que muestran el funcionamiento en tiempo real de todo el sistema, incluyendo el reconocimiento y la imitación de las expresiones faciales humanas.This paper presents a multi-sensor humanoid robotic head for human robot interaction. The design of the robotic head, Muecas, is based on ongoing research on the mechanisms of perception and imitation of human expressions and emotions. These mechanisms allow direct interaction between the robot and its human companion through the different natural language modalities: speech, body language and facial expressions. The robotic head has 12 degrees of freedom, in a human-like configuration, including eyes, eyebrows, mouth and neck, and has been designed and built entirely by IADeX (Engineering, Automation and Design of Extremadura) and RoboLab. A detailed description of its kinematics is provided along with the design of the most complex controllers. Muecas can be directly controlled by FACS (Facial Action Coding System), the de facto standard for facial expression recognition and synthesis. This feature facilitates its use by third party platforms and encourages the development of imitation and of goal-based systems. Imitation systems learn from the user, while goal-based ones use planning techniques to drive the user towards a final desired state. To show the flexibility and reliability of the robotic head, the paper presents a software architecture that is able to detect, recognize, classify and generate facial expressions in real time using FACS. This system has been implemented using the robotics framework, RoboComp, which provides hardware-independent access to the sensors in the head. Finally, the paper presents experimental results showing the real-time functioning of the whole system, including recognition and imitation of human facial expressions.Trabajo financiado por: Ministerio de Ciencia e Innovación. Proyecto TIN2012-38079-C03-1 Gobierno de Extremadura. Proyecto GR10144peerReviewe
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