A 2.5D BEM-FEM using a spectral approach to study scattered waves in fluid–solid interaction problems

42nd International Conference on Boundary Elements and other Mesh Reduction Methods, BEM/MRM 2019; ITeCons-University of Coimbra, Coimbra; Portugal; 2 July 2019 through 4 July 2019. - Publicado en WIT Transactions on Engineering Sciences, Volume 126, 2019, Pages 111-123This work presents a two-and-a-half dimensional (2.5D) spectral formulation based on the finite element method (FEM) and the boundary element method (BEM) to study wave propagation in acoustic and elastic waveguides. The analysis involved superposing two dimensional (2D) problems with different longitudinal wavenumbers. A spectral finite element (SFEM) is proposed to represent waveguides in solids with arbitrary cross-section. Moreover, the BEM is extended to its spectral formulation (SBEM) to study unbounded fluid media and acoustic enclosures. Both approaches use Lagrange polynomials as element shape functions at the Legendre–Gauss–Lobatto (LGL) points. The fluid and solid subdomains are coupled by applying the appropriate boundary conditions at the limiting interface. The proposed method is verified by means of a benchmark problem regarding the scattering of waves by an elastic inclusion. The convergence and the computational effort are evaluated for different h-p strategies. Numerical results show good agreement with the reference solution. Finally, the proposed method is used to study the pressure field generated by an array of elastic fluid-filled scatterers immersed in an acoustic mediumMinisterio de Economía y Competitividad BIA2016-75042-C2-1-

Seed beetles (Coleoptera: Bruchidae) associated with Acacia cornigera (L.) Willd., with description of a new species of Acanthoscelides Schilsky

Presented herein is a key to identify species of Bruchidae associated with Acacia cornigera (L.). For each species, host records, distributions and bionomics are given. A new species of Acanthoscelides Schilsky is described and figured; Acanthoscelides sauli Romero, Cruz, and Kingsolver

A novel 2.5D spectral approach for studying thin-walled waveguides with fluid-acoustic interaction

This paper presents a novel formulation of two spectral elements to study guided waves in coupled problems involving thin-walled structures and fluid-acoustic enclosures. The aim of the proposed work is the development of a new efficient computational method to study problems where geometry and properties are invariant in one direction, commonly found in the analysis of guided waves. This assumption allows using a two-and-a-half dimensional (2.5D) spectral formulation in the wavenumber-frequency domain. The novelty of the proposed work is the formulation of spectral plate and fluid elements with an arbitrary order in 2.5D. A plate element based on a Reissner-Mindlin/Kirchhoff-Love mixed formulation is proposed to represent the thin-walled structure. This element uses approximation functions to overcome the difficulties to formulate elements with an arbitrary order from functions. The proposed element uses a substitute transverse shear strain field to avoid shear locking effects. Three benchmark problems are studied to check the convergence and the computational effort for different strategies. Accurate results are found with an appropriate combination of element size and order of the approximation functions allowing at least six nodes per wavelength. The effectiveness of the proposed elements is demonstrated studying the wave propagation in a water duct with a flexible side and an acoustic cavity coupled to a Helmholtz resonator.Ministerio de Economía y Competitividad BIA2013-43085-P y BIA2016-75042-C2-1-RCentro Informático Científico de Andalucía (CICA

Cuantificación, caracterización y análisis de la comercialización de leña en Puerto Williams, Isla Navarino, Xll región

Romero, J.;Cruz, G. Facultad de Ciencias Forestales. Universidad de Chile. Santiago, Chile.Se cuantificó, caracterizó y analizó la comercialización de leña en Puerto Williams para el sector productores y comercializadores de leña, en términos de: métodos de extracción y acopio de leña, características de los productos ofertados y vías de comercialización; y para el sector consumidores de leña en cuanto a: forma de adquisición y almacenamiento de los productos, características del consumo de leña y utilización de gas licuado como combustible alternativo. Este último sector fue subdividido en subsectores: domiciliario, industrial y de servicios. Se obtuvo como resultado que la mayoría de los productores no realizan acopio de leña. Las unidades transadas poseen único precio de venta, y se comercializan principalmente en estado verde o semi-seco, y de modo informal. La máxima demanda por leña se concentra en el primer cuatrimestre del año, en tanto que la mínima demanda ocurre durante el último trimestre. El consumo anual total alcanza a aproximadamente 15.000 m3 sólidos, con participación de 65%, 30% y 5% por parte de los subsectores domiciliario, servicios e industria respectivamente. El consumo promedio de leña por vivienda es de 27,4 m3 sólidos /año; en tanto que para los servicios es de 127,1 m3 sólidos. Por último, cada industria utiliza un promedio anual de 720 m3 sólidos. La leña es utilizada fundamentalmente para calefacción. El gas licuado se usa principalmente para cocción de alimentos y obtención de agua caliente. La proporción de utilización de combustibles es altamente favorable para leña. Su participación en la matriz energética analizada (leña/gas licuado/petróleo) es del 71%.Proyecto FONDEF D02 I 108

Modified spinning black holes

In the context of f(R) modified gravity theories we determine that the black holes existence is determined by the sign of a parameter dependent of the mass, the charge, the spin and the scalar curvature. We obtain the different astrophysical objects derived from the presence of different horizons. Thermodynamics for this kind of black holes is studied for negative values of the curvature, revealing that we can distinguish between two kinds of BH: fast and slow.Comment: 4 pages, 6 figures, Contribution to the ERE2011 Spanish Relativity Meeting, Madrid 201

ELEMENTS INVOLVED IN THE TERRITORY BRAND FROM RESIDENTS’ PERCEPTION: THE CITY OF MÁLAGA

The brand might create a position of the territory that could be useful for the development of geographical spaces. It could also become a solid basis upon which to make decisions about the tourism planning of a city. This paper deals with the features, which are recognized by residents as those that are involved in the creation of Málaga brand. In order to achieve the goals set in this research, a descriptive methodology has been used. This study has been carried out using a questionnaire in which 1230 residents have participated. The findings have corroborated the hypotheses. Indeed, the results show that Málaga brand is being built under the concept of culture and that some places of the city are vital in the making of the territory image. This also encourages economic growth and hence employment. This paper offers important implications and tools to both public and private institutions insofar as they promote tourism promotion campaigns