A generalized operational formula based on total electronic densities to obtain 3D pictures of the dual descriptor to reveal nucleophilic and electrophilic sites accurately on closed-shell molecules

Indexación: Wiley Online Library. Online Version of Record published before inclusion in an issue http://onlinelibrary.wiley.com/doi/10.1002/jcc.24453/fullBy means of the conceptual density functional theory, the so-called dual descriptor (DD) has been adapted to be used in any closed-shell molecule that presents degeneracy in its frontier molecular orbitals. The latter is of paramount importance because a correct description of local reactivity will allow to predict the most favorable sites on a molecule to undergo nucleophilic or electrophilic attacks; on the contrary, an incomplete description of local reactivity might have serio us consequences, particularly for those experimental chemists that have the need of getting an insight about reactivity of chemical reagents before using them in synthesis to obtain a new compound. In the present work, the old approach based only on electronic densities of frontier molecular orbitals is replaced by the most accurate procedure that implies the use of total electronic densities thus keeping consistency with the essential principle of the DFT in which the electronic density is the fundamental variable and not the molecular orbitals. As a result of the present work, the DD will be able to properly describe local reactivities only in terms of total electronic densities. To test the proposed operational formula, 12 very common molecules were selected as the original definition of the DD was not able to describe their local reactivities properly. The ethylene molecule was additionally used to test the capability of the proposed operational formula to reveal a correct local reactivity even in absence of degeneracy in frontier molecular orbitals.http://onlinelibrary.wiley.com/doi/10.1002/jcc.24453/ful

Combined hydro-wind generation bids in a pool-based electricity market

Present regulatory trends are promoting the irect participation of wind energy in electricity markets. The final result of these markets sets the production scheduling for the operation time, including a power commitment from the wind generators. However, wind resources are uncertain, and the final power delivered usually differs from the initial power committed. This imbalance produces an overcost in the system, which must be paid by those who produce it, e.g., wind generators among others. As a result, wind farm revenue decreases, but it could increase by allowing wind farms to submit their bids to the markets together with a hydro generating unit, which may easily modify its production according to the expected imbalance. This paper presents a stochastic optimization technique that maximizes the joint profit of hydro and wind generators in a pool-based electricity market, taking into account the uncertainty of wind power prediction.En prens

Study of the urban heat island in Alicante

El fenómeno de isla de calor es tema actual y de gran trascendencia dentro de los estudios de clima urbano. A pesar de ello y de su tamaño poblacional, la ciudad de Alicante todavía no ha sido objeto de una investigación a fondo sobre dicha anomalía térmica. En este sentido, este artículo pretende de alguna manera iniciar estas investigaciones, dando lugar a unas primeras pautas de localización del máximo térmico y distribución de la isla de calor. Utilizando el método de los transectos se ha realizado la toma de temperaturas durante 10 días, dando lugar a la aparición de tres morfologías de isla de calor claramente definidas: la fuerte, débil y desplazada, que cuenta con un importante carácter geográfico. Así pues, podemos dar respuesta a una primera hipótesis sobre la existencia de este fenómeno en Alicante, puesto que de media, el centro de la isla marca 4,5ºC más de temperatura sobre el punto frío o áreas urbanas menos cálidas.The phenomenon of the urban heat island is a current and importance issue in the urban climate studies. In spite of this and its population size, the city of Alicante has not been the subject of in depth research about the thermal anomaly as mentioned before. In this sense, this article expects to start these investigations in some way, giving rise to the first guidelines of location of the thermal maximum and distribution of the heat island. Using the method of the transects, the temperature measures have been carried out for 10 days, giving rise to the emergence of three morphologies of urban heat island clearly defined: the strong, the weak and the urban heat island in motion, which has an important geographic nature. Therefore, we can respond to the first hypothesis on the existence of this phenomenon in Alicante since on average, the center of the island marks 4.5ºC warmer on the cold spot or urban areas less warm

Estomatitis i esofagitis en una tortuga mora associades a un nou adenovirus

En els rèptils, l'estomatitis infecciosa és la malaltia més comuna del tracte digestiu superior, i està causada per diferents infeccions bacterianes, fúngiques i virals. Investigadors de la UAB han observat per primera vegada com un nou tipus d'adenovirus ha desencadenat la malaltia en tortugues, concretament en un exemplar de tortuga mora (Testudo graeca) procedent d'una col·lecció privada.En los reptiles, la estomatitis infecciosa es la enfermedad más común del superior, y está causada por diferentes infecciones bacterianas, fúngi Investigadores de la UAB han observado por primera vez como un nuevo tipo d desencadenado la enfermedad en tortugas, concretamente en un ejemplar d (Testudo graeca) procedente de una colección privada

Fiscal decentralization, macrostability and growth

This paper examines how fiscal decentralization may influence economic growth. Previous research on this question has primarily focused on the potential direct relationship between decentralization and growth. In this paper, we also examine the potential indirect influence of decentralization on growth through its impact on macroeconomic stability. We find that decentralization may positively influence price stability in developed countries, though this impact is much less clear in developing and transitional countries. We also find some evidence suggesting that decentralization may directly and negatively affect economic growth in higher-income countries but that this effect is reduced through the indirect positive impact of decentralization on growth through macroeconomic stability.Fiscal Decentralization, Economic Growth, and Macroeconomic Stability.

La didáctica y la cognición de los ángulos negativos y mayores a 360º y sus funciones trigonométricas: un estudio en el nivel medio superior

El trabajo que desarrollamos en esta investigación tiene por objetivo analizar la relación que hay entre la didáctica y cognición de los ángulos negativos y mayores de 360º. Para ello se hizo un análisis de libros de texto utilizados por los profesores y alumnos, se propuso un cuestionario que fue aplicado a 19 estudiantes de nivel medio superior con un promedio de edad de 18 años; para con ello analizar las relaciones entre el discurso matemático escolar, las concepciones y representaciones de los alumnos. Cabe señalar que nosotros entendemos al proceso de definición del significado de los ángulos negativos y mayores a 360 grados como un proceso de convención matemática (Martínez-Sierra, 2003, 2005) para que las funciones trigonométricas sean periódicas y tengan sentido en los reales

Quantum Backreaction on Three-Dimensional Black Holes and Naked Singularities

We analytically investigate backreaction by a quantum scalar field on two rotating Ba\~nados-Teitelboim-Zanelli (BTZ) geometries: that of a black hole and that of a naked singularity. In the former case, we explore the quantum effects on various regions of relevance for a rotating black hole space-time. We find that the quantum effects lead to a growth of both the event horizon and the radius of the ergosphere, and to a reduction of the angular velocity, compared to the unperturbed values. Furthermore, they give rise to the formation of a curvature singularity at the Cauchy horizon and show no evidence of the appearance of a superradiant instability. In the case of a naked singularity, we find that quantum effects lead to the formation of a horizon that shields it, thus supporting evidence for the r\^ole of quantum mechanics as a cosmic censor in nature.Comment: 6 pages. Version to match the one published in Physical Review Letters. Apart from some reformatting, the main difference is that we now also include quantum backreaction effects on a rotating naked singularity as well as on a rotating black hole (both in (2+1)-dimensions

Quantum dress for a naked singularity

We investigate semiclassical backreaction on a conical naked singularity space-time with a negative cosmological constant in (2+1)-dimensions. In particular, we calculate the renormalized quantum stress-energy tensor for a conformally coupled scalar field on such naked singularity space-time. We then obtain the backreacted metric via the semiclassical Einstein equations. We show that, in the regime where the semiclassical approximation can be trusted, backreaction dresses the naked singularity with an event horizon, thus enforcing cosmic censorship.Comment: 7 pages, 1 figure. Version 2 contains very minor changes and matches the version published in Phys.Lett.