8,337 research outputs found
Concentrated Solar Power: Actual Performance and Foreseeable Future in High Penetration Scenarios of Renewable Energies
Producción CientíficaAnalyses proposing a high share of concentrated solar power (CSP) in future 100% renewable energy scenarios rely on the ability of this technology, through storage and/or hybridization, to partially avoid the problems associated with the hourly/daily (short-term) variability of other variable renewable sources such as wind or solar photovoltaic. However, data used in the scientific literature are mainly theoretical values. In this work, the actual performance of CSP plants in operation from publicly available data from four countries (Spain, the USA, India, and United Arab Emirates) has been estimated for three dimensions: capacity factor (CF), seasonal variability, and energy return on energy invested (EROI). In fact, the results obtained show that the actual performance of CSP plants is significantly worse than that projected by constructors and considered by the scientific literature in the theoretical studies: a CF in the range of 0.15–0.3, low standard EROI (1.3:1–2.4:1), intensive use of materials—some scarce, and significant seasonal intermittence. In the light of the obtained results, the potential contribution of current CSP technologies in a future 100% renewable energy system seems very limited.Ministerio de Economía, Industria y Competitividad (Project FJCI-2016-28833)European Union’s Horizon 2020 Research and Innovation Programme under Grant Agreement No. 69128
Un retablo en Boadilla de Rioseco (Palencia) de Santiago Carnicero y Tomás Sierra
El ensamblador Santiago Carnicero y el escultor Tomás de Sierra colaboraron en varias obras para la zona de Tierra de Campos entre los años finales del siglo XVII y las primeras décadas del siguiente. En este artículo se da a conocer el retablo de la ermita del Amparo de Boadilla de Rioseco (Palencia) y su proceso constructivo, poniéndolo en relación con algunas otras obras de ambos artistas barrocos.The joiner Santiago Carnicero and the sculptor Tomás de Sierra collaborated in some works in the area of Tierra de Campos between the final years of the XVIIth century and the first decades of the next one. In this article is presented the altarpiece of the Amparo hermitage in Boadilla de Rioseco (Palencia) and its making process, putting it in relation with other Works from both Baroque artists
El escultor Pedro de Bolduque: orígenes y primeras obras
El trabajo pretende ahondar en el conocimiento de los primeros años de Pedro de Bolduque, su nacimiento y formación en el taller de Maestre Mateo de Bolduque, la personalidad artística de su hermano mayor, Juan Mateo de Bolduque, y su participación en distintas obras hasta su asentamiento en Cuéllar (Segovia) a comienzos de la década de los 80 del siglo XVI. Se incluyen algunas aclaraciones sobre los retablos de Capillas (Palencia) y Santa María de Medina de Rioseco (Valladolid), donde estuvo bajo las órdenes de Juan de Juni, los dos principales conjuntos de estos primeros años.This paper tries to go deeper in the knowledge of Pedro de Bolduque's early years, his birth and his training in the workshop of Maestre Mateo de Bolduque, the artistic personality of his older brother, Juan Mateo de Bolduque, and his participation in different works until he settled down in Cuéllar (Segovia) at the beginning of the 80's, 16th Century. There are included some explanations about the altarpieces of Capillas (Palencia) and Santa María in Medina de Rioseco (Valladolid), where he was under the orders of Juan de Juni, the two main works of this early years
¿Es útil diferenciar a los interlocks de acuerdo con el tipo de consejero (ejecutivo o no ejecutivo) que los posee? Su influencia sobre el rendimiento de la empresa
Taking the assumptions of the resource dependency theory as our starting point, the main objective
of this investigation is to gain an understanding of how and in what way board members who serve
on multiple boards (interlocks) can affect a firm’s profitability, and whether it is useful to consider the
derivation of these interlocks according to the type of board member (executive or non-executive) who
possesses them. Using dynamic panel data analysis (GMM) and a sample of 88 firms quoted on the
Spanish Continuous Market for the period 2005–2008, our results confirm the existence of a curvilinear
(inverted-U) relation between interlocks and firm performance. The results demonstrate that this relation
is only significant if we include the total number of external ties rather than just the number of links
generated by non-executive directors. We can also confirm that the degree of familiarity and shared
knowledge between board members (measured by average board tenure) affects this relationship.Partiendo de los supuestos de la teoría de dependencia de recursos, el principal objetivo de esta investigación
pasa por conocer cómo y de qué forma la pertenencia de los consejeros a múltiples consejos
(interlocks) podría afectar a la rentabilidad de la empresa y si es importante considerar en esta relación
la procedencia de los interlocks según la tipología del consejero que lo ostente (consejeros ejecutivos
y no ejecutivos). Mediante un análisis de datos de panel dinámico (GMM), y a través de una muestra
de 88 empresas cotizadas en el Mercado Continuo espa˜nol para el periodo 2005–2008, los resultados
obtenidos confirman que existe una relación curvilínea (en forma de U invertida) entre los interlocks y el
rendimiento de la empresa, y que esta relación es sólo significativa si tenemos en cuenta el número total
de vínculos externos, y no sólo cuando tomamos en número de vínculos generados por los consejeros
no-ejecutivos. Asimismo, podemos afirman que el grado de familiaridad y conocimiento mutuo entre los
miembros del consejo (medido por la permanencia media del consejo) influye sobre esta relación
Del refranero agropecuario en el occidente astur
En número dedicado a: El Principado de de Asturia
Fiscal data revisions in Europe
Public deficit figures are subject to revisions, as most macroeconomic aggregates are. Nevertheless, in the case of Europe, the latter could be particularly worrisome given the role of fiscal data in the functioning of EU’s multilateral surveillance rules. Adherence to such rules is judged upon initial releases of data, in the framework of the so-called Excessive Deficit Procedure (EDP) Notifications. In addition, the lack of reliability of fiscal data may hinder the credibility of fiscal consolidation plans. In this paper we document the empirical properties of revisions to annual government deficit figures in Europe by exploiting the information contained in a pool of real-time vintages of data pertaining to fifteen EU countries over the period 1995-2008. We build up such real-time dataset from official publications. Our main findings are as follows: (i) preliminary deficit data releases are biased and non-efficient predictors of subsequent releases, with later vintages of data tending to show larger deficits on average; (ii) such systematic bias in deficit revisions is a general feature of the sample, and cannot solely be attributed to the behaviour of a small number of countries, even though the Greek case is clearly an outlier; (iii) Methodological improvements and clarifications stemming from Eurostat’s decisions that may lead to data revisions explain a significant share of the bias, providing some evidence of window dressing on the side of individual countries; (iv) expected real GDP growth, political cycles and the strength of fiscal rules also contribute to explain revision patterns; (v) nevertheless, if the systematic bias is excluded, revisions can be considered rational after two years. JEL Classification: E01, E21, E24, E31, E5, H600data revisions, fiscal statistics, news and noise, Rationality, real-time data
Effects of climate on wood formation of Quercus robur L. and Quercus pyrenaica Willd. along a mediterraneity gradient in Galicia: an Integrated analysis using phenology, anatomy, and dendroecology
This Thesis is focused on the study of seasonal dynamics of wood formation and non-structural carbohydrates, as well as on the climatic information contained in tree-ring series, in two ring-porous species with contrasting ecological strategies (Q. robur L. and Q. pyrenaica Willd.) along a water-availability gradient in Galicia. This integrative approach allows us to yield a detailed portrayal of the processes controlling wood formation, and their consequences on tree hydraulic functionality and the carbon balance. This research is particularly concerned about the environmental control of growth, whereby the obtained information is used to ascertain the responses of deciduous oaks to the ongoing environmental change
UIMP-TV. A window on the world
Análisis de la plataforma de emisión de contenidos en directo y en abierto de la Universidad Internacional Menéndez Pelayo, UIMP-TV, así como del ecosistema de algunas de las aplicaciones integradas en el proyecto educativo UIMP 2.0. En el presente documento especificamos los incentivos que llevaron a la Universidad Internacional Menéndez Pelayo a transformar su modelo docente para adaptarse a la aplicación de las nuevas tecnologías web 2.0 en el ámbito educativo. Definiremos las características técnicas del sistema, su metodología de trabajo y sus resultados y repercusión en la comunidad UIMP 2.0 y en las redes sociales generalistas en las que la UIMP tiene presencia.Analysis of the International University Menéndez Pelayo broadcast streaming platform and open live content called UIMP-TV, as well as the ecosystem of some of the applications related and integrated in the educational project UIMP 2.0.In this paper we specify the incentives that led to the International University Menéndez Pelayo to transform their teaching model to fit the application of new web 2.0 technologies in education. We define the technical characteristics of the system, its methodology and its results and impact on the UIMP 2.0 community and within the generalists social networks in which the International University Menéndez Pelayo is present
The board of directors and international decision-making
This paper develops a view of how specific elements of the directors' human and social
capital can enhance a company's international performance. We have taken the view that
the board is an active participant in the firm’s management, and we have therefore set out
and tested a number of arguments related to the board’s role in the adoption of international decisions. Specifically, our results point to the need to incorporate board members with high levels of education and international background with ability to learn and process information and to help international decision-making. As shown by our results, a high level of external connectivity of directors could have negative repercussions for internationalization since they limit the time spent on the board and therefore reduces the cohesion and trust inside the board. The implications of this research, therefore, are important for both executives and academics, as it helps to know what attributes contribute to the board’s effectiveness in such a way as to positively affect the internationalization of the firm
Standard, Point of Use, and Extended Energy Return on Energy Invested (EROI) from Comprehensive Material Requirements of Present Global Wind, Solar, and Hydro Power Technologies
Producción CientíficaWhether renewable energy sources (RES) will provide sufficient energy surplus to entirely power complex modern societies is under discussion. We contribute to this debate by estimating the current global average energy return on energy invested (EROI) for the five RES technologies with the highest potential of electricity generation from the comprehensive and internally consistent estimations of their material requirements at three distinct energy system boundaries: standard farm-gate (EROIst), final at consumer point-of-use (EROIfinal), and extended (including indirect investments, EROIext). EROIst levels found fall within the respective literature ranges. Expanding the boundaries closer to the system level, we find that only large hydroelectricity would currently have a high EROIext ~ 6.5:1, while the rest of variable RES would be below 3:1: onshore wind (2.9:1), offshore wind (2.3:1), solar Photovoltaic (PV) (1.8:1), and solar Concentrated Solar Power (CSP) (<1:1). These results indicate that, very likely, the global average EROIext levels of variable RES are currently below those of fossil fuel-fired electricity. It remains unknown if technological improvements will be able to compensate for factors, which will become increasingly important as the variable RES scale-up. Hence, without dynamically accounting for the evolution of the EROI of the system, the viability of sustainable energy systems cannot be ensured, especially for modern societies pursuing continuous economic growthMEDEAS project, funded by the European Union’s Horizon2020 research and innovation programme under grant agree-ment no. 691287LOCOMOTION project, funded by the EuropeanUnion’s Horizon 2020 research and innovation programmeunder grant agreement no. 82110
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