11037 research outputs found
Sort by
Halide perovskite photocatalysts for clean fuel production and organic synthesis: opportunities and challenges
Full text linkThe need to constrain the use of fossil fuels causing global warming is motivating the development of a variety of photocatalysts for solar‐to‐fuel generation and chemical synthesis. In particular, semiconductor‐based photocatalysts have been extensively exploited in solar‐driven organic synthesis, carbon dioxide (CO 2 ) conversion into value‐added products, and hydrogen (H 2 ) generation from water (H 2 O) splitting. Recently, metal halide perovskites (MHPs) have emerged as an important class of semiconductors for heterogeneous photocatalysis owing to their interesting properties. Despite key issues with long‐term stability and degradation in polar solvents due to their ionic character, there has been significant progress in halide perovskite‐based photocatalysts with improving their stability and performance in the gas and liquid phases. This review discusses the state‐of‐the‐art for using halide perovskite‐based photocatalysts and photoelectrocatalysis in hydrogen production from water and halogen acid solutions, CO 2 reduction into value‐added chemicals, and various organic chemical transformations. The different types of halide perovskites used, design strategies to overcome the instability issues in polar solvents, and the efficiencies achieved are discussed. Furthermore, the outstanding challenges associated with the use of polar electrolytes and how the stability and performance can be improved are discussed.Agencia Estatal de Investigación | Ref. PID2023-147567NB-I00Agencia Estatal de Investigación | Ref. TED2021-131628A-I00Agencia Estatal de Investigación | Ref. CNS2022-135531Agencia Estatal de Investigación | Ref. RYC2018-026103-IXunta de Galicia | Ref. ED431F2021/05UK Research and Innovation | Ref. EP/X029900/1Royal Academy of Engineering | Ref. RCSRF2324‐18‐68Engineering and Physical Sciences Research Council | Ref. EP/T026219/1Engineering and Physical Sciences Research Council | Ref. EP/W017091/1Engineering and Physical Sciences Research Council | Ref. EP/X038777/
Poesía reunida. X. L. Méndez Ferrín
No full text[inicio] Xénese e organización do corpus poético
O farto río da poesía de Ferrín é toda unha longa aventura de accidentado, especial e vivo discurso. É por iso que non ten unha doada organización editorial. Varias das súas obras víronse sometidas a diferentes peripecias, sobre todo debidas ó contexto político adverso, que supuxeron alteracións ás veces graves dos proxectos. Por non falar das lóxicas autocorreccións do autor, que tampouco son especialmente significativas no seu caso. Por estes e outros motivos houbo tamén importante dispersión da súa creación poética, que o propio poeta quixo corrixir, proceso no que nós tamén aquí nos empeñamos, pero que seguramente non é aínda un proceso rematado dada a diversidade de ámbitos literarios, políticos e sociais nos que Méndez Ferrín participou coa súa poesía. En todo caso, o noso criterio é sempre respectar as decisións inequivocamente tomadas polo autor e tratar de ofrecerlle ó lector unha organización con certa lóxica, que a continuación nos propomos explicar, de todo este diverso e vasto conxunto. [...
Succession agreements in Galicia. Ineffectiveness of the pacto de mejora
No full textTranscurridos diez años desde la promulgación de la Ley 2/2006, de 14 de junio, de Derecho civil de Galicia, resulta conveniente abordar una de las dificultades que su interpretación y aplicación ha suscitado (Disposición Adicional Primera), tal es la parca regulación de la ineficacia de los pactos de mejora, al incluir únicamente en su articulado las causas que la provocan, obviando cualquier previsión referida a los efectos que su concurrencia pueda desencadenar, con la excepción contemplada en su art. 217.2. En el presente trabajo abordaremos el estudio, no sólo de las causas de ineficacia de los pactos de mejora, incluida la mejora de labrar y poseer, sino también de los efectos que su presencia provoca en cuanto a una posible restitución de bienes y frutos o abono
de gastos, sin olvidarnos de la trascendencia de una eventual pérdida por el mejorado de todos o parte de los bienes transmitidos ni de los efectos respecto de terceros cuando los pactos de mejora sean con entrega de bienes de presente
Rosalía de Castro. La flor, A mi madre, poesía dispersa e traducións
No full text[Inicio] Coa publicación deste volume quixemos recoller, despois de Cantares gallegos (2013), Follas novas (2016) e En las orillas del Sar (2019), o resto da produción poética de Rosalía de Castro. Agrupar nun mesmo volume dous libros e toda a poesía dispersa, incluíndo as traducións, igual lles resta protagonismo a La flor e a A mi madre, ou mesmo á poesía dispersa, pero é que no proxecto editorial anunciado agora hai case dez anos concibimos un número determinado de volumes, polo que se nos fai indispensable que cada un deles vaia integrando o conxunto seguindo este criterio. [...
La arquitectura del agua en la ciudad de Compostela en tiempos del arzobispo Diego Gelmírez (1100-1140) y su fortuna en Galicia
No full textAssessment criteria for seed accelerators in entrepreneurial project selections
No full textThis paper contributes to the literature on accelerators by filling the gap concerning the criteria used to select venture projects. Seed accelerators develop strict and rated assessment criteria for project selection that grants them objectivity and guarantees program success. This study uses a sample of 309 cases to analyse the criteria applied by an accelerator when selecting projects. Among these cases, 15 entered the accelerator stage. Our work first examines variables linked to the business project, such as the extent of innovation, extent of investability, speed of acceleration and extent of team consistency. It then assesses entrepreneurial skills such as negotiation, teamwork, creativity, communication and leadership. Our findings show that extent of team consistency and speed of acceleration are the most widely-used variables to assess a business project, while the most valued entrepreneurial skills are leadership followed by creativity. Furthermore, the project is more likely to enter the acceleration stage in the presence of higher team consistency and creativity
Non-destructive approach for the generation and thermal characterization of an as-built BIM
No full textBuilding Information Models are being increasingly accepted as containers and managers of data during the lifecycle of buildings, given their capacity of associating the descriptive data available, such as the physical properties of the materials, with the 3D representation of the building. In the case of existing buildings, as-built BIMs have to be created, and non-destructive techniques are required to acquire all the information needed provoking no disruption or change to the building. In this work, the as-built BIM of a facility is created through the semi-automated processing of a laser scanning point cloud and enriched with the different U-values of the enclosure. This thermophysical property is obtained for the construction as-is through an energy balance using temperature values measured with a thermographic camera. The resulting as-built BIM is defined according to the gbXML language, which was especially created to be used in analysis of the performance of the building.Xunta de GaliciaMinisterio de Educación, Cultura y Deporte | Ref. FPU AP2010-2969Ministerio de Educación, Cultura y Deporte | Ref. FPU AP2009-114
Detección de fraude y de manipulación de beneficios a través de un caso de estudio: evidencia de una empresa familiar internacional
Full text linkThe aim of this study is to estimate the probability of fraud and earnings management for a specific Spanish family business, Pescanova. In the context of financial statements, the Beneish model is used to detect fraudulent behavior. Our findings reveal that Pescanova presented propensity to commit fraud and carried out aggressive accounting practices before the disclosure of its financial problems. The manipulation index and the probability of manipulation are used as indicators of fraud and earnings management. Results also show that Pescanova made aggressive accounting practices, through the manipulation of Day's sales in receivables index and Total accruals to total assets. Next, we provided evidence that the Sales Growth index and Leverage index are aligned with the position of technical default shown by the pre-bankruptcy board of Pescanova. Our main contribution is demonstrating the validity of the model for the case of Pescanova. Therefore, the application of the Beneish model might have detected fraudulent behavior, in the years prior to Pescanova's collapse.El objetivo de este estudio es estimar la probabilidad de fraude y de manipulación de beneficios para una empresa familiar española, Pescanova. En el contexto de los estados financieros, se utiliza el modelo Beneish para detectar el comportamiento fraudulento. Nuestros resultados revelan que Pescanova presentaba propensión a cometer fraude y que llevó a cabo prácticas contables agresivas, antes de revelar sus problemas financieros. El índice de manipulación y la probabilidad de manipulación, han sido usados como indicadores de fraude y de gestión de beneficios. Los resultados también muestran que Pescanova llevó a cabo prácticas contables agresivas a través de la manipulación de índices como, Ventas diarias sobre cuentas por cobrar y Devengos totales sobre activos totales. Además, se aporta evidencia empírica de que el índice de crecimiento de ventas y el índice de endeudamiento, están alineados con el informe reportado por la Administración concursal. Nuestra principal contribución es la demostración de la validez del modelo para el caso Pescanova. Por lo tanto, la aplicación del modelo Beneish podría haber detectado el comportamiento fraudulento de la empresa, en los años previos al colapso de Pescanova.Ministerio de Educación, Cultura y Deporte | Ref. FPU-15/0339
Bayesian multi-proxy reconstruction of early Eocene latitudinal temperature gradients
Full text linkAccurately reconstructing large-scale palaeoclimatic patterns from sparse local records is critical for understanding the evolution of Earth's climate. Particular challenges arise from the patchiness, uneven spatial distribution, and disparate nature of palaeoclimatic proxy records. Geochemical data typically provide temperature estimates via transfer functions derived from experiments. Similarly, transfer functions based on the climatic requirements of modern taxa exist for some fossil groups, such as pollen assemblages. In contrast, most ecological and lithological data (e.g. coral reefs and evaporites) only convey information on broad climatic requirements. Historically, most large-scale proxy-based reconstructions have used either geochemical or ecological data, but few studies have combined multiple proxy types into a single quantitative reconstruction. Large spatial gaps in existing proxy records have often been bridged by simple averaging, without taking into account the spatial distribution of samples, leading to biased temperature reconstructions. Here, we present a Bayesian hierarchical model to integrate ecological data with established geochemical proxies into a unified quantitative framework, bridging gaps in the latitudinal coverage of proxy data. We apply this approach to the early Eocene climatic optimum (EECO), the interval with the warmest sustained temperatures of the Cenozoic. Assuming the conservation of thermal tolerances of modern coral reefs and mangrove taxa, we establish broad sea surface temperature ranges for EECO coral reef and mangrove sites. We integrate these temperature estimates with the EECO geochemical shallow marine proxy record to model the latitudinal sea surface temperature gradient and global average temperatures of the EECO. Our results confirm the presence of a flattened latitudinal temperature gradient and unusually high polar temperatures during the EECO, which is supported by high-latitude ecological data. We show that integrating multiple types of proxy data, and adequate prior information, has the potential to enhance quantitative palaeoclimatic reconstructions, improving temperature estimates from datasets with limited spatial sampling.Agencia Estatal de Investigación | Ref. FJC2021-046695-
Dos experimentos sobre el uso de condicionales
No full textEn el presente trabajo se describen y analizan dos experimentos empíricos a partir de los que se pretende extraer algunos indicios con respecto al uso que los hablantes hacemos de los enunciados condicionales en el lenguaje cotidiano (español). El primero de ellos trata de mostrar que ciertos enunciados con aparente formato condicional pueden tener varias interpretaciones para diversos hablantes de una lengua. Algunas de estas interpretaciones no poseen forma condicional. El segundo de los experimentos trata de indagar si esta diversidad de interpretaciones puede influir en los sujetos a la hora de establecer el valor veritativo de los enunciados originales. Aunque el presente estudio puede ser interesante tanto para lingüistas como para filósofos analíticos o lógicos que consideren relevante la observación del uso que los hablantes de español hacen de expresiones del tipo "Si... entonces...", se pretende que este estudio contribuya a clarificar algunas cuestiones relativas al tratamiento de expresiones condicionales en el ámbito del procesamiento del lenguaje natural.In this paper two empirical experiments are described and analysed. From these experiments we are trying to get some indications on the use of conditional statements in common language (Spanish). By means of the first experiment, we are trying to show that some statements -which could be considered as conditionals- are interpreted in different ways by some speakers, and some of those interpretations do not have conditional form. With the second experiment, we are trying to study whether those different interpretations are relevant to establish the truth value of the original statements. This study could be interesting for linguists, analytic philosophers or logicians who consider the use of "si ... entonces ... " ["if ... then ... " ] expressions by Spanish speakers as an important matter. But the main objective of this work is to clarify some questions about the treatment of conditional expressions in Natural Language ProcessingMinisterio de Ciencia e Innovación | Ref. FFI2009-08828Ministerio de Educación y Ciencia | Ref. HUM2006-0495