Evolving temporal conceptual schemas: the reification case

We study temporal conceptual schema evolutions related to reification, a typical and complex modeling construct. Various types of reification are considered. Using a previously defined framework, we specify only at conceptual level (and without descending to logical or application levels), the effects of any possible evolution related to reification, thus reducing the complexity of the management of those changes.Peer ReviewedPostprint (published version

On the equilibrium of pricing assignment for heterogeneous wireless access networks

Next generation networks and service providers are rapidly evolving in order to satisfy the demands of an increasing number of users. Nowadays, one of the most relevant research lines in the Heterogeneous Wireless Access Networks realm is the use of procedures and mechanisms so as to provide intelligence to the network, with the main goal of optimizing its performance. Furthermore, mobile communication users are becoming more demanding, and thus it becomes essential for the providers to be able to offer a competitive value for money. This paper pursues the objective of obtaining, from an analytical perspective, the optimum price assignment strategy according to the characteristics of a particular scenario, analyzing the improvement attained with such optimum pricing policy as compared to a more traditional one. Game theory techniques, which are gathering the interest within the communications scientific community, are used for the analysis.Preprin

Gas phase selective hydrogenation of furfural to furfuryl alcohol and 2-methylfuran over Cu-CeO2 coprecipitated catalysts

Furfural is an important chemical derived from lignocellulosic biomass, in particular from C5 sugars like xylose, and it is considered as a platform molecule of great potential for the synthesis of a broad spectrum of chemicals. In this sense, furfuryl alcohol and 2-methylfuran are two important chemicals which can be produced through furfural hydrogenation, either in liquid or vapor phase, although the latter is preferred because it can be carried out at atmospheric pressure. Industrially, a copper chromite catalyst is used, although this catalyst can become very toxic due to the presence of chromium. Therefore, much attention is being paid to the development of chromium-free catalysts, more sustainable and environmentally friendly, as those based on Cu or Ni which are active and selective towards the formation of furfuryl alcohol and 2-methylfuran. Furfuryl alcohol is mainly used for the production of thermostatic resins, intermediate in the manufacture of lysine, vitamin C and dispersing agents. Meanwhile, 2-methyl furan is used in the synthesis of pesticides, or in the pharmaceutical and fragrance industries. The aim of this work is the synthesis of a series of copper based catalysts, which have been synthesized by coprecipitation of copper and cerium(IV) and subsequent thermal programmed reduction. This method allows increasing the dispersion of Cu particles, while the use of a support like CeO2 can modify the electronic density of the active phase, which can influence the catalytic activity and resistance to deactivation.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Economy and Competitiveness Ministry (Project CTQ2012-38204-C03-02), Junta de Andalucía (Project: RNM-1565) and FEDER funds of the European Unio

Mesoporous niobium oxide for dehydration of D-xylose into furfural

Se ha demostrado que el óxido de niobio mesoporoso es un catalizador eficaz para la deshidratación de D-xilosa a furfural, alcanzando una conversión del 92% y un rendimiento de furfural 49,3% a 170º C y 90 minutos. La lixiviación de Nb, determinada por ICP-MS, era inferior al 0,5% en peso de la concentración de Nb inicial, confirmando de este modo la estabilidad del catalizador ácido sólido.El furfural posee un gran potencial como molécula plataforma de origen renovable para la síntesis de una alta variedad de compuestos químicos. Se obtiene mediante la deshidratación de pentosas, principalmente a partir de D-xilosa, proceso catalizado por ácidos minerales en fase homogénea. Por tanto, dentro de la química verde y la búsqueda de sostenibilidad de los procesos catalíticos, es necesaria su sustitución por catalizadores sólidos ácidos que sean tolerantes al agua, ya que es el disolvente más utilizado para esta reacción. El óxido de niobio posee propiedades ácidas y es insoluble en agua, pero su superficie específica es muy baja. Por lo tanto, resulta muy interesante la síntesis de un óxido de niobio mesoporoso para emplearlo como catalizador en esta reacción. En este trabajo, se ha sintetizado un Nb2O5 mesoporoso y se ha evaluado su comportamiento catalítico en la obtención de furfural a partir de D-xilosa.Spanish Ministry of Science and Innovation (ENE2009-12743-C04-03 project)Junta de Andalucía (P09-FQM-5070).Ministry of Science and Innovation for the financial support under the Program Ramón y Cajal (RYC-2008-03387)

Jugando con Android : acciones

El proyecto global está enfocado al aprendizaje del desarrollo de aplicaciones para el sistema operativo Android. Para ello, se pretende realizar una aplicación a través de la cual se puedan adquirir conocimientos de los diversos componentes que forman la estructura de la plataforma. Con ello, este proyecto pretende también ser una pequeña guía para aquellas personas que, cómo nosotros, pretenden iniciarse en el desarrollo de aplicaciones para Android. La aplicación desarrollada será un juego del género lucha, para uno o dos jugadores en el mismo terminal.El projecte global estarà enfocat al aprenentatge del desenvolupament d'aplicacions per al sistema operatiu Android. Per això, es pretén realitzar una aplicació a traves de la qual es puguin adquirir coneixements dels diversos components que formen l'estructura de la plataforma. Amb això, aquest projecte pretén també ser una petita guia per aquelles persones que, com nosaltres, pretenen iniciar-se en el desenvolupament d'aplicacions per Android. L'aplicació desenvolupada serà un joc del gènere de lluita, per un o dos jugadors en el mateix terminal.The whole project is focused to learning to develop applications for Android operating system. To this end, is intended to make an application through which we can acquire knowledge of the differents components that form the platform structure. Thus, this project is also intended as a brief guide for those who, like us, are intended to start to develop applications for Android

Exploring the ring-closing metathesis for the construction of the solomonamide macrocyclic core: identification of bioactive precursors

New synthetic strategies directed toward the novel cyclopeptides solomonamides have been explored utilizing an olefin metathesis as the key reaction. In the various strategies investigated, we worked on minimally oxidized systems, and the olefin metathesis reaction demonstrated efficiency and validity for the construction of the macrocyclic core. The described synthetic strategies toward the solomonamides are well suited for the subsequent access to the natural products and represent flexible and diversityoriented routes that allow for the generation of a variety of analogues via oxidative transformations. In addition, preliminary biological evaluations of the generated solomonamide precursors revealed antitumor activity against various tumor cell lines.This work was financially supported by the Ministerio de Economía y Competitividad (MINECO) (ref BIO2014-56092-R, CTQ2014-60223-R and CTQ2016-76311-R) and Junta de Andalucía and “Fondo Europeo de Desarrollo Regional-FEDER” (P12 CTS-1507). I.C.-S. thanks Ministerio de Educación, Cultura y Deporte for a predoctoral fellowship (FPU programme)

Adaptive slope voltage control for distributed generation inverters with improved transient performance

© 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Reactive power injection in distributed generation inverters is an useful ancillary service for grid supporting purposes. For grid-feeding converters, the slope control method is the most common voltage regulation strategy used in local (communication-less) applications. Despite its simplicity, this method offers limited dynamic properties in scenarios with changing operation conditions. In this sense, this paper presents an adaptive slope voltage control which provides an improved transient performance against operating variations. To derive the control configuration, a control-oriented mathematical model is developed. The accuracy of the modeling and the performance of the proposed control are validated by selected experimental results.Peer ReviewedPostprint (author's final draft

Mussel-Inspired Lego Approach for Controlling the Wettability of Surfaces with Colorless Coatings

The control of surface wettability with polyphenol coatings has been at the forefront of materials research since the late 1990s, when robust underwater adhesion was linked to the presence of L-DOPA—a catecholic amino acid—in unusually high amounts, in the sequences of several mussel foot proteins. Since then, several successful approaches have been reported, although a common undesired feature of most of them is the presence of a remnant color and/or the intrinsic difficulty in fine-tuning and controlling the hydrophobic character. We report here a new family of functional catechol-based coatings, grounded in the oxidative condensation of readily available pyrocatechol and thiol-capped functional moieties. The presence of at least two additional thiol groups in their structure allows for polymerization through the formation of disulfide bonds. The synthetic flexibility, together with its modular character, allowed us to: (I) develop coatings with applications exemplified by textiles for oil-spill water treatment; (II) develop multifunctional coatings, and (III) fine-tune the WCA for flat and textile surfaces. All of this was achieved with the application of colorless coatings.Fil: Casagualda, Carolina. Universitat Autònoma de Barcelona; EspañaFil: Mancebo Aracil, Juan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; Argentina. Universitat Autònoma de Barcelona; EspañaFil: Moreno Villaecija, Miguel Angel. Universitat Autònoma de Barcelona; EspañaFil: López Moral, Alba. Universitat Autònoma de Barcelona; EspañaFil: Alibés, Ramon. Universitat Autònoma de Barcelona; EspañaFil: Busqué, Félix. Universitat Autònoma de Barcelona; EspañaFil: Ruiz Molina, Daniel. Universitat Autònoma de Barcelona; Españ

Magnetitas utilizadas para la obtención de alcohol furfurílico a partir de furfural mediante transferencia catalítica de hidrógeno

El furfural es considerado como una molécula plataforma debido a su alta reactividad en procesos de hidrogenación, oxidación, alquilación o deshidratación, originando una gran variedad de productos de alto valor añadido. En la presente comunicación se presentan los resultados obtenidos en el proceso de hidrogenación de furfural mediante transferencia catalítica de hidrógeno a partir de la reacción de Meerwein, Ponndorf y Verley, usando magnetitas como catalizador ácido, donde se ha variado la relación molar Fe(II)/Fe(III) empleada para su síntesis.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Invocació explícita versus invocació implícita: anàlisi comparativa de dos enfocaments de disseny de sistemes d'informació

The main goal of this work is to develop an initial characterization of an information systems design approach that we call implicit invocation and to analyse its potential advantatges and disadvantatges with respect to the conventional approach that we call explicit invocation. Our work tries to contribute to this approach at the specific field of object oriented design of information systems. In our analysis we use an example that consist in some simplified banking operations, that we use as basis for the comparation of the alternative designs we explore. We characterize what could be implicit invocation in information systems design, we apply this characterization to the example, and we present a comparative analysis of the two designs.Postprint (published version