University of Seville

About: University of Seville is a education organization based out in Seville, Andalucía, Spain. It is known for research contribution in the topics: Population & Model predictive control. The organization has 20098 authors who have published 47317 publications receiving 947007 citations. The organization is also known as: Universidad de Sevilla.

Rayleigh-Taylor breakdown for the Muskat problem with applications to water waves

Abstract: The Muskat problem models the evolution of the interface between two different fluids in porous media. The Rayleigh-Taylor condition is natural to reach linear stability of the Muskat problem. We show that the Rayleigh-Taylor condition may hold initially but break down in finite time. As a consequence of the method used, we prove the existence of water waves turning.

Coumarin derivatives for dye sensitized solar cells: a TD-DFT study

Abstract: Time dependent density functional theory (TD-DFT) calculations have been carried out to study the electronic structure and the optical properties of five coumarin based dyes: C343, NKX-2311, NKX-2586, NKX-2753 and NKX-2593. We have found out that the position and width of the first band in the electronic absorption spectra, the absorption threshold and the LUMO energy with respect to the conduction band edge are key parameters in order to establish some criteria that allow evaluating the efficiency of coumarin derivatives as sensitizers in Dye Sensitized Solar Cells (DSSC). Those criteria predict the efficiency ordering for the coumarin series in good agreement with the experimental evidence. Presumably, they might be used in the design of new efficient organic based DSSC.

Porin expression in clinical isolates of Klebsiella pneumoniae.

Abstract: Two porins, OmpK36 and OmpK35, have been described previously in Klebsiella pneumoniae, and they are homologous to the Escherichia coli porins OmpC and OmpF, respectively, at both the DNA and amino acid levels. Optimal resolution of the two K. pneumoniae porins by electrophoresis on polyacrylamide gels is not achieved using gel systems already described for E. coli and requires modifications of the bisacrylamide content of the resolving gels. Once resolved, identification of porins OmpK36 and OmpK35 cannot be based solely on their apparent molecular masses since in some strains the OmpK36 porin migrates faster than the OmpK35 porin, whilst in other strains OmpK35 is the faster-migrating porin. Expression of OmpK35 porin is increased in low-osmolarity medium and, combined with Western blot analysis, this allows for the identification of both porins. Application of this identification system showed that most isolates lacking expression of extended-spectrum β-lactamases express the two porins, whereas most isolates producing these β-lactamases express only porin OmpK36, and the OmpK35 porin is either very low or not expressed.

Requirements engineering for web applications: a comparative study

Abstract: The requirements engineering discipline has become more and more important in the last years. Tasks such as the requirements elicitation, the specification of requirements or the requirements validation are essential to assure the quality of the resulting software. The development of Web systems usually involves more heterogeneous stakeholders than the construction of traditional software. In addition, Web systems have additional requirements for the navigational and multimedia aspects as well as for the usability as no training is possible. Therefore a thoroughly requirements analysis is even more relevant. In contrast, most of the methodologies that have been proposed for the development of Web applications focus on the design paying less attention to the requirements engineering. This paper is a comparative study of the requirements handling in Web methodologies showing trends in the use of techniques for capturing, specifying and validating Web requirements.