Numerical representation of the quality measures of triangles and triangular meshes

In this note a new procedure to represent the quality measure for triangles is proposed. The triangles are identified by their three angles and are represented in a bounded domain, called angle representation region, according to the area co-ordinates, which are common and well known by finite element users. The developed representation can also be used in order to visualize the characteristics of any quality measure. This new procedure is extended to graphically represent triangular meshes in the angle representation region

Abnormal quality detection and isolation in water distribution networks using simulation models

This paper proposes a model based detection and localisation method to deal with abnormal quality levels based on the chlorine measurements and chlorine sensitivity analysis in a water distribution network. A fault isolation algorithm which correlates on line the residuals (generated by comparing the available chlorine measurements with their estimations using a model) with the fault sensitivity matrix is used. The proposed methodology has been applied to a District Metered Area (DMA) in the Barcelona network

Double excitation transitions in Mn2+ -doped alkali halides

4 págs.; 4 figs.It is shown in this work that the room-temperature excitation spectra of as-grown crystals of LiF, NaF, NaCl, KCl, and KBr doped with Mn2+ reveal the existence of double excitation peaks. These peaks are related to the formation of precipitated phases containing Mn2+ in the alkali halide lattice. In the case of LiF:Mn2+ the position of the [A14(G), E4(G)] and T14(G) peaks suggests an anomalously small Mn2+- F- distance for the precipitated phase. © 1983 The American Physical Society.Financial support by the Comision Asesora para la Investigacion Cientifica y Tecnica, is gratefully acknowledged.Peer Reviewe

Evolución de la innovación educativa en la Universidad Complutense: proyecto UNICOMEX

La evolución de la educación universitaria en España ha experimentado una enorme evolución en los últimos veinte años. Desde la enseñanza centrada en la clase magistral, con el consiguiente protagonismo del profesor, a lo que sucede actualmente, con el estudiante como eje principal, media todo un cambio en el planteamiento de nuestro sistema educativo universitario. La implantación del Espacio Europeo de Educación Superior (EEES) ha sido uno de los objetivos perseguidos por la Universidad Complutense de Madrid (UCM) en la última década. Con este fin existieron, hasta hace poco, las conocidas como Asignaturas Piloto (AP) e igualmente se convocan periódicamente, desde hace años, los Proyectos de Innovación Educativa (P.I.E.). Ambas herramientas han procurado facilitar dicha adaptación, así como promover un concepto transversal en la transmisión del conocimiento. Nuestro grupo de trabajo puede ser un ejemplo de lo que la UCM ha querido conseguir con ambas cosas. La asignatura ha participado en todas las convocatorias de AP, pasando por una evolución clara desde la clase magistral a los pequeños grupos de trabajo. Ha sido, además, el instrumento útil para ir desarrollando distintos P.I.E., hasta un total de nueve, tras formar un equipo interdisciplinar constituido por profesores universitarios y profesionales de diversos ámbitos. El último de estos PIE, concedido en el curso académico 2011-2012, consiste en la creación de un espacio virtual de referencia para el estudio de los animales exóticos, partiendo de los resultados obtenidos en proyectos anteriores. UNICOMEX (Universidad-Complutense-Exóticos) nace con el objetivo de poner al alcance de cualquiera una serie de recursos virtuales ordenados que faciliten el conocimiento biológico, anatómico y clínico de los animales exóticos, entendiendo como tales aquellos que, siendo de interés veterinario, no se consideran domésticos. La totalidad de su contenido está en español e inglés, con el fin de hacer de ella una herramienta virtual útil y abierta a la comunidad científica y didáctica internacional

The use of the SeDeM diagram expert system for the formulation of Captopril SR matrix tablets by direct compression

The SeDeM Diagram Expert System has been used to study excipients, Captopril and designed formulations for their galenic characterization and to ascertain the critical points of the formula affecting product quality to obtain suitable formulations of Captopril Direct Compression SR Matrix Tablets. The application of the Sedem Diagram Expert System enables selecting excipients with in order to optimize the formula in the preformulation and formulation studies. The methodology is based on the implementation of ICH Q8, establishing the design space of the formula with the use of experiment design, using the parameters of the SeDeM Diagram Expert System as system responses

Efficient and reliable nonlocal damage models

We present an efficient and reliable approach for the numerical modelling of failure with nonlocal damage models. The two major numerical challenges––the strongly nonlinear, highly localized and parameter-dependent structural response of quasi-brittle materials, and the interaction between nonadjacent finite elements associated to nonlocality––are addressed in detail. Reliability of the numerical results is ensured by an h-adaptive strategy based on error estimation. We use a residual-type error estimator for nonlinear FE analysis based on local computations, which, at the same time, accounts for the nonlocality of the damage model. Efficiency is achieved by a proper combination of load-stepping control technique and iterative solver for the nonlinear equilibrium equations. A major issue is the computation of the consistent tangent matrix, which is nontrivial due to nonlocal interaction between Gauss points. With computational efficiency in mind, we also present a new nonlocal damage model based on the nonlocal average of displacements. For this new model, the consistent tangent matrix is considerably simpler to compute than for current models. The various ideas discussed in the paper are illustrated by means of three application examples: the uniaxial tension test, the three-point bending test and the single-edge notched beam test.Peer ReviewedPostprint (author’s final draft

Mesh management methods in finite element simulations of orthodontic tooth movement

In finite element simulations of orthodontic tooth movement, one of the challenges is to represent long term tooth movement. Large deformation of the periodontal ligament and large tooth displacement due to bone remodelling lead to large distortions of the finite element mesh when a Lagrangian formalism is used. We propose in this work to use an Arbitrary Lagrangian Eulerian (ALE) formalism to delay remeshing operations. A large tooth displacement is obtained including effect of remodelling without the need of remeshing steps but keeping a good-quality mesh. Very large deformations in soft tissues such as the periodontal ligament is obtained using a combination of the ALE formalism used continuously and a remeshing algorithm used when needed. This work demonstrates that the ALE formalism is a very efficient way to delay remeshing operations