Informe resumen de las visitas de evaluación al proyecto de electrificación rural en la v sección de la provincia de Pacajes (La Paz). 1998

Informe resumen de las visitas de evaluación al Proyecto de Electrificación Rural en la V sección de la Provincia de Pacajes (La Paz) en Bolivia, durante julio y agosto de 1998, realizadas por el autor en el marco de la evaluación y estudio del Programa de Electrificación Rural en el altiplano boliviano realizado con la participación de IPADE y AECID (1990 – 1998

Informe resumen del programa de electrificación rural en el altiplano boliviano con participación de IPADE y AECI (1990 – 1998)

Informe resumen del Programa de Electrificación Rural en el altiplano boliviano realizado con la participación de IPADE y AECID (1990 – 1998), realizado por el autor en el marco de la evaluación y estudio de dicho programa y los proyectos que lo desarrollan

Intrinsic and extrinsic factors that influence consumers’ intention and purchase behavior: The case of eco-labeled dairy products

This research aims to undersatnd how intrinsic and extrinsic factors can influence consumers’ buying decision on shopping eco-labeled dairy products in order to close the gap between intention and purchase. This research is a quantitative study and uses the theory of reasoned action (TRA) of Ajzen & Fishbein (1980). Data were collected through surveys applied to consumers buying dairy products from a recognised dairy supermarket in Bogotá-Colombia. This work uses logistic regression as a statistical method to subsequently complement the analysis and enhance the results. It also uses exploratory factor analysis, confirmatory analysis, and a structural equation model. Findings show that ecological labels do not generate a positive influence to close the gap between intention and purchase. Manufacturers should strengthen environmental damage knowledge and awareness on dairy products consumption while keeping positive private benefits so that eco-labels really work and the gap between intention and purchase can be reduced.Tesi

Key aspects in 3D fatigue crack closure numerical modelling

Since long time, fatigue crack closure has been studied by means of finite element models. Initially by bi-dimensional models and recently, due to the higher computational capabilities, the use of three-dimensional models has been extended, providing a wider comprehension of the problem. Starting with the methodology used for 2D cases, a specific methodology for 3D models has been developed. Key parameters affecting the model have been analyzed and recommendations have been established. The numerical accuracy is evaluated in terms of crack closure and opening values. They main issues studied are the material behaviour, the loading cycles and crack growth scheme, the contact simulation, the meshing and the element size at the crack tip and along the thickness, the plastic wake computed and the opening and closure definition considered. This paper summarises the main learning and recommendations from the latest numerical modelling experience of the authors.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

3D numerical study of the transient behaviour on plasticity induced crack closure

Daniel Camas, Fernando Antunes, Pablo Lopez-Crespo, Antonio Gonzalez-Herrera, 3D Numerical Study of the Transient Behaviour on Plasticity Induced Crack Closure, Abstract Booklet of the MSMF9, Edited by Pavel Sandera, Brno University of Technology, 2019, pp. 136.The numerical analysis of the plasticity induced crack closure requires the development of the plastic wake. Transient behaviour is observed when the crack starts to grow. The plastic wake length has an influence on the crack closure results and a great impact on the computational cost. Previous works have analysed the influence of this parameter considering bi-dimensional specimens in either plane strain or plane stress conditions. Lately, some three-dimensional models have appeared in order to analyse the crack closure phenomenon. The main scope of this study is to quantify and comprehend the minimum length required to stabilise the crack opening and closure values considering a three-dimensional model. On this purpose, a CT aluminium specimen has been modelled three-dimensionally and several calculations have been made in order to evaluate the influence of the simulated plastic wake. The numerical analysis is made in terms of crack closure and opening values.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

A numerical analysis of the plastic wake influence on plasticity induced crack closure

Fatigue crack closure has been studied by means of finite element method since long time ago. Most work has been performed considering bi-dimensional models. Lately, the use of threedimensional models has been extended. Nevertheless, the methodology employed has been taken from that developed for bi-dimensional cases. There are a great number of previous bi-dimensional studies which analyse different numerical parameters and optimise them. The current computational capabilities allow a comprehensive study of the influence of the different modelling parameters in a similar way to those studies carried out with bidimensional models, with the advantage, that the evolution along the thickness of the analysed parameters can be taken into consideration. In particular, one of the key issues is related to the plastic wake length which is developed during the previous loading cycles. This residual stresses have a great influence on the crack opening and closure values. As the numerical analysis are complex and computationally expensive, the length of the simulated wake is a critical parameter. In this work, a comprehensive study of the effect of the plastic wake in fatigue crack closure is made. On this purpose, a CT aluminium specimen has been modelled three-dimensionally and several calculations have been made in order to evaluate the influence of the simulated plastic wake length. The numerical analysis is made in terms of crack closure and opening values as in terms of the stress and strain fields near the crack front.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Technologies and capability approach: a framework for solar energy development projects

The implementation of solar energy development projects in isolated rural communities involves a large technological change for the beneficiaries. Despite these development projects imply direct basic need coverage (in terms of energy access and its benefit) its success is dependent on many aspect difficult to understand. Experience shows that the same technology may be successful or not depending on many external factors. These technological projects are commonly formulated based on two simple accepted premises. The first one relies on the general assumption that beneficiaries would accept and be more involved in a project in direct relation to their human needs satisfaction that the project provides. The second one, particular for this kind of project, is that simple technology is better understood and so accepted, maintained and properly used by the beneficiaries, in the wake of the intermediate technology movement. Reality shows that both assumptions are not always observed in these projects. Surprisingly, some solar energy solution with better link with human need satisfaction are not well accepted while other -with higher complexity- are used and adapted for long time use. A different framework must be used to explain short and long term behavior of these projects and capability approach and the conversion factor concept provide a good framework to understand the process involving high tech in development projects This work intends to apply the well-known capability approach as a theoretical framework to identify the conversion factors through which a solar energy project -considered as a good- promotes capabilities and so, achieved functioning. The theoretical consideration is based on field notes about solar energy projects in Bolivia. Particularly a set of development projects performed in the 90's decade and sponsored by the Spanish Agency for International Development Cooperation (AECID) have been the object of short and long-term analysis. They were focused on rural electrification on Bolivian Altiplano (high plateau) and several solar energy solutions have been implemented at different stages of the program. They show how the same technology achieves positive or negative capacity developments depending on the context, and that we could identify the conversion factors that promote a successful project. In this sense a link could be establish among this Capability Approach framework and the commonly used Logical Framework Approach, among conversion factor and assumptions (external factor) at certain levels.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Informe resumen de las visitas al proyecto de electrificación rural en la v sección de la provincia de Pacajes (La Paz) 2009

El presente documento recoge de una manera general la información obtenida durante la visita realizada a la V Sección de la Provincia de Pacajes (La Paz), en septiembre de 2009, por los autores para la valoración y estudio del proyecto de electrificación rural ejecutado por IPADE y AECI - OTC Bolivia desde 1996 a 1998

INFLUENCE OF THREE DIMENSIONAL FINITE ELEMENT MESH SIZE ON PLASTICITY INDUCED CRACK CLOSURE PHENOMENON

In the present work, a CT aluminium specimen has been modelled three-dimensionally and several calculations have been made in order to evaluate the influence of the mesh size around the crack front. The numerical accuracy is analysed in terms of crack closure and opening values as in terms of the stress and strain fields near the crack front. Classical bi-dimensional recommendations are updated

Gravitational lensing by wave dark matter halos

Wave Dark Matter (WaveDM) has recently gained attention as a viable candidate to account for the dark matter content of the Universe. In this paper we explore the extent to which dark matter halos in this model, and under what conditions, are able to reproduce strong lensing systems. First, we analytically explore the lensing properties of the model -- finding that a pure WaveDM density profile, a soliton profile, produces a weaker lensing effect than other similar cored profiles. Then we analyze models with a soliton embedded in an NFW profile, as has been found in numerical simulations of structure formation. We use a benchmark model with a boson mass of $m_a=10^{-22}{\rm eV}$, for which we see that there is a bi-modality in the contribution of the external NFW part of the profile, and actually some of the free parameters associated with it are not well constrained. We find that for configurations with boson masses $10^{-23}$ -- $10^{-22}{\rm eV}$, a range of masses preferred by dwarf galaxy kinematics, the soliton profile alone can fit the data but its size is incompatible with the luminous extent of the lens galaxies. Likewise, boson masses of the order of $10^{-21}{\rm eV}$, which would be consistent with Lyman-$\alpha$ constraints and consist of more compact soliton configurations, necessarily require the NFW part in order to reproduce the observed Einstein radii. We then conclude that lens systems impose a conservative lower bound $m_a > 10^{-24}$ and that the NFW envelope around the soliton must be present to satisfy the observational requirements.Comment: 26 pages, 7 figures, Publishe