RETRASO, a code for modeling reactive transport in saturated and unsaturated porous media

The code RETRASO (REactive TRAnsport of SOlutes) simulates reactive transport of dissolved and gaseous species in non-isothermal saturated or unsaturated problems. Possible chemical reactions include aqueous complexation (including redox reactions), sorption, precipitation-dissolution of minerals and gas dissolution. Various models for sorption of solutes on solids are available, from experimental relationships (linear KD, Freundlich and Langmuir isotherms) to cation exchange and surface complexation models (constant capacitance, diffuse layer and triple layer models). Precipitation-dissolution and aqueous complexation can be modelled in equilibrium or according to kinetic laws. For the numerical solution of the reactive transport equations it uses the Direct Substitution Approach. The use of the code is demonstrated by three examples. The first example models various sorption processes in a smectite barrier. The second example models a complex chemical system in a two dimensional cross-section. The last example models pyrite weathering in an unsaturated medium

Lo esencial del desarrollo sustentable para jóvenes y no tan jóvenes

Lo esencial del desarrollo sustentable para jóvenes y no tan jóvenes, es un libro publicado en el año 2014, por la editorial Fontamara y la Universidad Autónoma de Querétaro, México. Se trata de una primera edición y consta de 167 páginas. La autora de este libro es doctora en Psicología del Desarrollo Cognoscitivo por la Escuela de Altos Estudios en Ciencias Sociales en París, Francia. Por la calidad de sus estudios e investigaciones ha sido invitada especial para desarrollar actividades de docencia en algunas instituciones educativas de Europa y América del Sur. Es miembro en varias asociaciones académicas y de investigación en el ámbito nacional e internacional, principalmente en Europa.Lo esencial del desarrollo sustentable para jóvenes y no tan jóvenes, es un libro publicado en el año 2014, por la editorial Fontamara y la Universidad Autónoma de Querétaro, México. Se trata de una primera edición y consta de 167 páginas. La autora de este libro es doctora en Psicología del Desarrollo Cognoscitivo por la Escuela de Altos Estudios en Ciencias Sociales en París, Francia. Por la calidad de sus estudios e investigaciones ha sido invitada especial para desarrollar actividades de docencia en algunas instituciones educativas de Europa y América del Sur. Es miembro en varias asociaciones académicas y de investigación en el ámbito nacional e internacional, principalmente en Europa.Universidad Autónoma del Estado de México Centro de Investigación Multidisciplinaria en Educación Colegio de Ciencias Geográficas del Estado de México, A. C

A finite strain, finite band method for modeling ductile fracture

We present a finite deformation generalization of the finite thickness embedded discontinuity formulation presented in our previous paper [A.E. Huespe, A. Needleman, J. Oliver, P.J. Sánchez, A finite thickness band method for ductile fracture analysis, Int. J. Plasticity 25 (2009) 2349–2365]. In this framework the transition from a weak discontinuity to a strong discontinuity can occur using a single constitutive relation which is of importance in a range of applications, in particular ductile fracture, where localization typically precedes the creation of new free surface. An embedded weak discontinuity is introduced when the loss of ellipticity condition is met. The resulting localized deformation band is given a specified thickness which introduces a length scale thus providing a regularization of the post-localization response. The methodology is illustrated through several example problems emphasizing finite deformation effects including the development of a cup-cone failure in round bar tension.A.E.H. and P.J.S. are grateful for financial support from ANPCyT and CONICET of Argentina through grants: PICT 2006-01232, PICT 2008-1228 and PIP 112-200901-00341. J.O. is grateful for financial support from the Spanish Ministry of Science and Innovation and the Catalan Government Research Department, under grants BIA2008-00411 and 2009 SGR 1510, respectively.Peer ReviewedPostprint (author's final draft

Fate of MTBE and DCPD Compounds Relative to BTEX in Gasoline-Contaminated Aquifers

The aim of this communication is to provide preliminary results on MTBE monitoring, and at the same time to propose some new tracers of gasoline pollution in groundwater. An overview is presented on benzene-toluene-ethylbenzene-xylene (BTEX), methyl tertiary-butyl ether (MTBE), and dicyclopentadienes (DCPD) contents in gasoline formulations. Their specific fate in gasoline-contaminated aquifers are consistent with their physical-chemical properties

Stabilized mixed finite elements with embedded strong discontinuities for shear band modeling

A stabilized mixed finite element with elemental embedded strong discontinuities for shear band modeling is presented. The discrete constitutive model, representing the cohesive forces acting across the shear band, is derived from a rate-independent J2 plastic continuum material model with strain softening, by using a projection-type procedure determined by the Continuum-Strong Discontinuity Approach. The numerical examples emphasize the increase of the numerical solution accuracy obtained with the present strategy as compared with alternative procedures using linear triangles.Peer ReviewedPostprint (author's final draft

Un modelo constitutivo de daño plástico para materiales friccionales. Parte I: variables fundamentales, funciones de fluencia y potencial

En este artículo se presenta un modelo constitutivo elasto-plástico, que permite simular el comportamiento inultiaxial del hormigón, utilizando funciones de fluencia plástica homogéneas de primer grado en las tensiones. En particular, se presenta una modificación del criterio de Mohr-Coulomb y un nuevo criterio de fluencia que concuerda bastante bien con los resultados experimentales. También se formulan las variables fundamentales que utiliza el modelo, como son las variables internas de daño plástico y cohesión, y las funciones de fricción y dilatancia. Se trata adeimás, el problema de la objetividad en la respuesta, y su relación con la energía específica.Peer Reviewe

Continuous chip formation in metal cutting processes using the Particle Finite Element Method (PFEM)

This paper presents a study on the metal cutting simulation with a particular numerical technique, the Particle Finite Element Method (PFEM) with a new modified time integration algorithm and incorporating a contact algorithm capability . The goal is to reproduce the formation of continuous chip in orthogonal machining. The paper tells how metal cutting processes can be modelled with the PFEM and which new tools have been developed to provide the proper capabilities for a successful modelling. The developed method allows for the treatment of large deformations and heat conduction, workpiece-tool contact including friction effects as well as the full thermo-mechanical coupling for contact. The difficulties associated with the distortion of the mesh in areas with high deformation are solved introducing new improvements in the continuous Delaunay triangulation of the particles. The employment of adaptative insertion and removal of particles at every new updated configuration improves the mesh quality allowing for resolution of finer-scale features of the solution. The performance of the method is studied with a set of different two-dimensional tests of orthogonal machining. The examples consider, from the most simple case to the most complex case, different assumptions for the cutting conditions and different material properties. The results have been compared with experimental tests showing a good competitiveness of the PFEM in comparison with other available simulation tools.Peer ReviewedPostprint (published version

Un modelo constitutivo de daño plástico para materiales friccionales. Parte II: Generalización para procesos con degradación de rigidez: ejemplos

Peer Reviewe

Bonuses and Penalties as Equilibrium Incentive Devices, with Application to Manufacturing Systems

Although psychologists view bonuses and penalties as very different means of providing incentives for workers, economists have had less success at making sense of the distinction. A rational worker should be indifferent as to whether a payment scheme is called a bonus or a penalty plan if the actual contingent pay stream is identical in the two cases. In this paper we provide a framework for understanding the difference between payment plans that are deemed to be penalty or bonus schemes, and derive implications for when such plans should be implemented as a function of observable features of the manufacturing and monitoring systems. We call a payment plan a "bonus" scheme if the high payment occurs infrequently in equilibrium; a payment scheme entails a possible "penalty" if the low wage occurs infrequently. The frequency of high and low payments is derived in equilibrium in a model with moral hazard and probabilistic monitoring. We focus on the role of commitment and the possibility of false positives in he monitoring technology. It is shown that when the firm can commit to a monitoring intensity the workers will (almost) always be diligent and a penalty scheme will be observed. When commitment is infeasible the optimal payment structure depends on whether the monitoring technology permits false positives. In the absence of false positives the workers will be observed to face a penalty scheme if found shirking, but when false positives are possible there will be considerable shirking by workers in equilibrium, and a bonus scheme will be observed. We then analyze the crucial features of our theoretical monitoring technology in he context of actual employment situations. We find that middle-management and other non-production jobs are appropriate for bonus-type incentives, whereas in unskilled jobs or aspects of highly skilled jobs that require diligence but not skill, such as arriving on the job on time, we predict penalty incentives. We argue that the observed scarcity of penalty-type schemes can be explained by our model, without resorting to psychological justifications. In addition, we interpret the Japanese manufacturing systems as having a particular, built-in monitoring system that can be analyzed in our framework and shown to implement a high level of diligence from factory workers.

GAP WORK project report: training for youth practitioners on tackling gender-related violence

This project sought to challenge gender-related violence against (and by) children and young people by developing training for practitioners who have everyday contact with general populations of children and young people (‘youth practitioners’). Through improved knowledge and understanding practitioners can better identify and challenge sexist, sexualising, homophobic or controlling language and behaviour, and know when and how to refer children and young people to the most appropriate support services. This summary outlines the Project and our initial findings about the success of the four training programmes developed and piloted.Co-funded by the DAPHNE III programme of the EU