Structures and Stabilities of Doubly-charged (MgO)nMg2+ (n=1-29) Cluster Ions

Ab initio perturbed ion plus polarization calculations are reported for doubly-charged nonstoichiometric (MgO)nMg2+ (n=1-29) cluster ions. We consider a large number of isomers with full relaxations of the geometries, and add the correlation correction to the Hartree-Fock energies for all cluster sizes. The polarization contribution is included at a semiempirical level also for all cluster sizes. Comparison is made with theoretical results for neutral (MgO)n clusters and singly-charged alkali-halide cluster ions. Our method is also compared to phenomenological pair potential models in order to asses their reliability for calculations on small ionic systems. The large coordination-dependent polarizabilities of oxide anions favor the formation of surface sites, and thus bulklike structures begin to dominate only after n=24. The relative stabilities of the cluster ions against evaporation of a MgO molecule show variations that are in excellent agreement with the experimental abundance spectra.Comment: Final version accepted in Journal of Chemical Physics; 8 pages plus 8 figures (6 GIFs and 2 PSs). The main difference with respect to the original submission is the inclusion of coordination-dependent polarizabilities for oxide anions. That results in substantial changes in the result

Modulational instability windows in the nonlinear Schr\"odinger equation involving higher-order Kerr responses

We introduce a complete analytical and numerical study of the modulational instability process in a system governed by a canonical nonlinear Schr\"odinger equation involving local, arbitrary nonlinear responses to the applied field. In particular, our theory accounts for the recently proposed higher-order Kerr nonlinearities, providing very simple analytical criteria for the identification of multiple regimes of stability and instability of plane-wave solutions in such systems. Moreover, we discuss a new parametric regime in the higher-order Kerr response which allows for the observation of several, alternating stability-instability windows defining a yet unexplored instability landscape.Comment: 9 pages, 8 figure

The Rothschild House business network in Spain as an example of entrepreneurial decision-taking and management structure.

In the period between 1835 and 1931 the Rothschild House established one of the most complex and influential business networks in Spanish economic history. This network controlled a wide range of activities, including financial services for the Spanish Government and the Bank of Spain, as well as the management of industrial, mining and railway firms. Instances of these firms are Rio Tinto Co., Société Minière et Metallurgique Peñarroya, MZA railway company and Deutsch & Cie, which was the main oil refining firm in Spain at the end of the 19th century.Spain 1835-1931, Rothschild, networks, Weisweiller, Bauer, foreign investments in Spain, railways, mining and refining companies, international raw material market, Public Finances, entrepreneurial function, agency problems, rent-seeking.

La percolación cultural o cómo el mercado se institucionaliza en el tercer sector

Proponemos el concepto de percolación cultural para describir y estudiar el fenómeno de la introducción en el tercer sector de los valores propios de las organizaciones del mercado. Para ello, se describe un marco teórico que incluye teorías sobre la cultura organizacional, el nuevo institucionalismo y la teoría relacional de la sociedad como mejor herramienta para conocer el tercer sector. Se explicitan las hipótesis que han guiado la investigación y la metodología que la hizo posible y se refieren los principales hallazgos. En el nivel macro, se observa la percolación a través de dos tipos de comportamiento organizacional diferenciado; en el plano micro, se atiende a los factores ideológicos que dificultan la percolación; en el meso, se relaciona la percolación cultural con factores de naturaleza material. El análisis se realizó a partir de datos secundarios de 87 ONGD, 28 entrevistas semiestructuradas y una encuesta realizada al personal de 24 organizaciones.In this article the concept of cultural percolation is used to describe and study the introduction of values of for-profit organizations in the Third Sector. We propose a theoretical frame that includes theories on organizacional culture, the relational theory of society and the new institutionalism. This article specifies several hypotheses and the methodology to verify them, and presents the results of the research carried out at three levels: First, at macro level, the cultural percolation is observed in two types of organizational behavior; second, at micro level, ideological factors which obstruct the cultural percolation are described; and third, at meso level, the cultural percolation are influenced by material factors. The analysis is based on secundary data of 87 Developmental Non Governmental Organizations and primary analysis of data from 28 semiestructurated intervews and a survey to the personnel of 24 organziations

The short summer of tourismphobia. Social movements and urban conflict in the neighborhood of Poblenou, Barcelona

L’any 2017 podria ser considerat, a Barcelona, com l’any de la turismefòbia. Els canvis socials i econòmics viscuts per la ciutat durant les darreres dècades s›han vist acompanyats per l’aparició de tot un entramat de moviments socials íntimament lligats a aquestes transformacions, així com als seus impactes. Al barri del Poblenou, el diagnòstic realitzat per #EnsPlantem, Veïns en Perill d’Extinció, apunta a la turistificació com un dels seus principals reptes. Mitjançant una aproximació etnogràfica de dos anys al voltant d’aquesta plataforma, el present article pretén mostrar el paper exercit per aquest tipus de moviments davant de l’aplicació de polítiques urbanes contemporànies de tall neoliberal vinculades al turisme.The year 2017 could be considered, in Barcelona, as the year of tourismphobia. The social and economic changes experienced by the city during the last decades have been accompanied by a complex network of social movements closely linked to these transformations, as well as their impacts. In the neighborhood of Poblenou, the diagnosis made by #EnsPlantem, Neighbors in Danger of Extinction, points to the touristification as one of its main challenges. Through an ethnographic approach of two years around this platform, this article aims to show the role played by this type of movements around the application of neoliberal contemporary urban policies linked to tourism