5,098 research outputs found

    A probabilistic model for explaining the points achieved by a team in football competition. Forecasting and regression with applications to the Spanish competition

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    In the last decades, a lot of research papers applying statistical methods for analysing sports data have been published. Football, also called soccer, is one of the most popular sports all over the world organised in national championships in a round robin format in which the team reaching the most points at the end of the tournament wins the competition. The aim of this work is to develop a suitable probability model for studying the points achieved by a team in a football match. For this purpose, we built a discrete probability distribution taking values, zero for losing, one for a draw and three for a victory. We test its performance using data from the Spanish Football League (First division) during the 2013-14 season. Furthermore, the model provides an attractive framework for predicting points and incorporating covariates in order to study the factors affecting the points achieved by the teams.Peer Reviewe

    The Sustainable Management of Metals: An Analysis of Global Research

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    The objective of this study was to analyze research trends in the field of sustainable management of metals on a global level between 1993 and 2017. To do so, a bibliometric analysis was carried out on a total of 6967 articles. The results revealed the growing interest in this research field, particularly over the last five year-period during which 63% of all articles were published. The three journals in which most articles had been published were the Journal of Cleaner Production, ACS Sustainable Chemistry and Engineering, and Chemsuschem. The countries that published the most articles were China, the United States, India, Germany, and the United Kingdom. A sizeable network of collaboration has been established between countries for the joint publication of studies. The main lines of research have been focused on metal decontamination in water and soil, waste management oriented towards reuse and recycling, and the innovation of processes for cleaner and more efficient production. The results revealed the need for comprehensive studies that integrate different disciplines within the same analytical framework, and to promote research that contributes to the different dimensions of sustainability (environmental, economic, and social)

    Los santucos montañeses

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    En número dedicado a: La provincia de Santande

    Exploring the effect of using carbon black in the sol-gel synthesis of BaMnO3 and BaMn0.7Cu0.3O3 perovskite catalysts for CO oxidation

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    BaMnO3 and copper-doped BaMnO3 perovskites seem to be a feasible alternative to current catalysts for the exhaust treatment. In this work, these formulations have been synthesized by a modified sol-gel method in which carbon black has been added to the conventional sol-gel process in order to improve the physical and chemical properties that modulate the catalytic performance. The samples have been deeply characterized by ICP-OES, XRD, XPS, H2-TPR and O2-TPD. The characterization results point out that the use of carbon black allows decreasing the calcination temperature which minimizes the sintering effects and improves the textural properties, the reducibility, and the oxygen mobility. The study of CO oxidation, using different simulated atmospheres, reveals that all the catalysts were active for CO to CO2 oxidation, but only when oxygen is supplied in excess, an effect of the synthesis method is observed. Additionally, as expected, the presence of copper (inserted or not into the perovskite lattice) benefits the catalytic performance. Otherwise, it seems that the catalytic performance for CO oxidation of BaMnO3-based samples is less affected by the fluctuations of CO and O2 concentrations than the platinum-based catalyst used as reference

    Analyzing the role of copper in the soot oxidation performance of BaMnO3-perovskite-based catalyst obtained by modified sol-gel synthesis

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    A series of BaMn0.7Cu0.3O3 solids were prepared by a modified sol-gel method in which carbon black (VULCAN XC-72R), and different calcination temperatures (BMC3-CX, where X indicates the calcination temperature) have been used. The fresh and used catalysts were characterized by ICP-OES, XRD, XPS, FESEM, TEM, O2-TPD and H2-TPR. The presence of a carbon black during sol-gel synthesis of BMC3 mixed oxide allows diminishing the calcination temperature needed to achieve the perovskite structure, but it hinders the formation of the BaMnO3 polytype. The use of low calcination temperatures during synthesis reduces the sintering effects, and the mixed oxides present lower particle size, slightly higher BET surface areas and macropores with lower diameter than BMC3. The distribution of copper in BMC3-CX catalysts depends on the calcination temperature and copper insertion into the perovskite structure is promoted as the calcination temperature increases. All BMC3-CX catalysts are active for NO to NO2 and NOx-assisted soot oxidation processes, but only BMC3-C600 and BMC3-C700 show higher catalytic activity than BMC3 reference catalyst. BMC3-C600 presents the best performance as it features a high amount of surface copper and oxygen vacancies that increase during reaction. The comparison between the performance of the two best catalysts of the BM-CX series (BM-C700) and the BMC3-CX series (BMC3-C600) suggests that the unique advantage of using copper in the modified sol-gel synthesis is an additional decrease of 100 °C in the calcination temperature used for the synthesis of the best catalyst, which is 700 °C for BM-CX and 600 °C for BMC3-CX.This research was funded by Spanish Government (PID2019-105542RB-I00) and EU (FEDER Founding)

    Modified BaMnO3-Based Catalysts for Gasoline Particle Filters (GPF): A Preliminary Study

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    Gasoline engines, mainly gasoline direct injection engines (GDI) require, in addition to three-way catalysts (TWC), a new catalytic system to remove the formed soot. Gasoline Particle Filters (GPF) are, among others, a possible solution. BaMnO3 and copper-doped BaMnO3 perovskites seem to be a feasible alternative to current catalysts for GPF. The physical and chemical properties of these two perovskites determining the catalytic performance have been modified using different synthesis routes: (i) sol-gel, (ii) modified sol-gel and iii) hydrothermal. The deep characterization allows concluding that: (i) all samples present a perovskite-like structure (hexagonal), except BMC3 which shows a polytype one (due to the distortion caused by copper insertion in the lattice), and ii) when a low calcination temperature is used during synthesis, the sintering effect decreases and the textural properties, the reducibility and the oxygen mobility are improved. The study of soot oxidation simulating the hardest GDI scenarios reveals that, as for diesel soot removal, the best catalytic performance involves the presence of oxygen vacancies to adsorb and activate oxygen and a labile Mn (IV)/Mn (III) redox pair to dissociate the adsorbed oxygen. The combination of both properties allows the transport of the dissociated oxygen towards the soot.This research was funded by Generalitat Valenciana (CIPROM/2021/70), Spanish Government (PID2019-105542RB-I00) and EU (FEDER Founding)

    Double or nothing: red flag symptoms of critical carotid stenosis, a case report

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    Abstract Background Detailed knowledge of every possible manifestation of Internal Carotid Artery (ICA) disease is important. For improving detection and a timely adoption of secondary prevention procedures or treatments. Transient oculomotor nerve palsies have been described associated with stenosis or occlusion of the ICA. Case presentation We described a patient that develop a sequential combination of transient monocular loss of vision followed by binocular diplopia secondary to an unstable atherosclerotic preocclusive stenosis of an internal carotid artery previously treated with radiotherapy. Conclusions The peculiar sequence of transient monocular vision that give rise later into a transient binocular diplopia (double or nothing) should be kept in mind as a possible manifestation of critical stenosis of ICA

    Assessment Scores in Morphological Competitions of Pura Raza Español Horse

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    The aim of this work was to establish the external factors affecting morphological scores in competitions of Pura Raza Español (PRE – Spanish Purebred) horses. The dataset included 8633 participations, in 69 different morphological competitions of 5097 horses, belonging to 1113 studs. In total, the dataset had 21,760 records (each with eight partial morphological scores) with a balanced frequency of males and females. Our results showed that there are several external factors that influence the judges’ scores. Morphological competition (15.70% of the total variance), judge (9.65%), judge*morphological competition (7.45%) and judge*type (2.41%) were the most important external factors in the analyzed traits. The reliability of judgements was evaluated by the index of disagreement, and results showed that it might be necessary to train judges to get more agreement in these scores. Moreover, for a breeding program it is very important that judges use all the range of scores in order to collect the maximum level of variation. The analyses showed that competitions with three judges were the most appropriate. © 2014 Friends Science Publisher

    A Framework to Evaluate Software Developer’s Productivity The VALORTIA Project

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    Currently, there is a lack in companies developing software in relation to assessing their staff’s productivity before executing software projects, with the aim of improving effectiveness and efficiency. QuEF (Quality Evaluation Framework) is a framework that allows defining quality management tasks based on a model. The main purpose of this framework is twofold: improve an entity’s continuous quality, and given a context, decide between a set of entity’s instances on the most appropriate one. Thus, the aim of this paper is to make this framework available to evaluate productivity of professionals along software development and select the most appropriate experts to implement the suggested project. For this goal, Valortia platform, capable of carrying out this task by following the QuEF framework guidelines, is designed. Valortia is a platform to certify users' knowledge on a specific area and centralize all certification management in its model by means of providing protocols and methods for a suitable management, improving efficiency and effectiveness, reducing cost and ensuring continuous quality.Ministerio de Ciencia e Innovación TIN2013-46928-C3-3-
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