SUSTENTABILITAT CLIVELLADA. DE LA GESTIÓ HIDROLÒG ICA A L’OBRA HIDRÀULICA AL VINALOPÓ MOD ERN

Davant la crisi d’insustentabilitat dels ecosistemes aquàtics, hem de revisar les nocions bàsiques per a canviar la visió actual de rius i aqüífers. Per la qual cosa és indispensable plantejar el procés històric de formació d’aquest problema socioecològic. Com era la gestió de l’aigua a les comunitats rurals del Vinalopó a l’època moderna? Quines idees i coneixements aplicava el camperolat tardofeudal quan utilitzava i/o s’apropiava del medi natural i, per tant, de l’aigua? A partir del llegat històric i patrimonial dels segles XVII i XVIII també deduïm els primers clivells a la gestió hidrològica ecointegradora de la comunitat rural i el pas a les grans obres hidràuliques que trenquen la sustentabilitat del cicle de l’aigua i dels seus ecosistemes.In light of the crisis of unsustainability of aquatic ecosystems, the basic notions must be reviewed in order to change the current perception of rivers and aquifers. It is therefore essential to consider how this socio-ecological problem was historically constructed. How was water managed in rural communities of the River Vinalopó during the modern era? What ideas and knowledge did the late-feudal peasantry apply when using and/or taking over the natural environment, and therefore the water? From the historic and patrimonial legacy of 17th and 18th centuries we also learn about the first breaches of eco-conciliatory hydraulic management of the rural community. From there we see the transition to big hydraulic works which break the sustainability of the water cycle and its ecosystems

Oversampling in shift-invariant spaces with a rational sampling period

8 pages, no figures.It is well known that, under appropriate hypotheses, a sampling formula allows us to recover any function in a principal shift-invariant space from its samples taken with sampling period one. Whenever the generator of the shift-invariant space satisfies the Strang-Fix conditions of order r, this formula also provides an approximation scheme of order r valid for smooth functions. In this paper we obtain sampling formulas sharing the same features by using a rational sampling period less than one. With the use of this oversampling technique, there is not one but an infinite number of sampling formulas. Whenever the generator has compact support, among these formulas it is possible to find one whose associated reconstruction functions have also compact support.This work has been supported by the Grant MTM2009-08345 from the D.G.I. of the Spanish Ministerio de Ciencia y Tecnología

Novas tendências em marketing por causa do auge da Internet

The use of Internet has changed considerably the marketing practice. In this article the authors carry on a literature review to analyse the factors involved in the process and also the advantages, challenges and opportunities of this technology from a marketing perspective.El uso de Internet ha traído cambios considerables para la práctica del Marketing. Este artículo lleva a cabo una revisión bibliográfica donde se analizan los factores que están relacionados con el proceso de cambio así como las ventajas, desafíos y oportunidades que ofrece esta nueva tecnología desde una perspectiva del Marketing.O uso da Internet trouxe mudanças consideráveis para a prática do Marketing. Este artigo realiza uma revisão bibliográfica onde se analisam os fatores que estão relacionados com o processo de mudança assim como as vantagens, desafios e oportunidades oferecidas por esta nova tecnologia a partir de uma perspectiva de Marketing

Rutting prediction of a granular material for base layers of low-traffic roads

[Abstract:] This paper analyses the permanent deformation performance of an unbound granular material for base layers of low-traffic roads. The material has been subjected to repeated triaxial loads. The shakedown theory was used to classify the structural response of the unbound granular material to the applications of load cycles. Three models were fitted to express the cumulative permanent strain as a function of the number of load cycles. In general, the predictions of two models previously studied by other researchers proved to be good but in the long-term, they tended to underestimate the measured values. In contrast, a third new model – the sum of two well known models – offered excellent predictions, which in the long-term did not tend to either underestimate or overestimate the measured values

Análisis de la respuesta elástica no lineal de las capas de base conformadas con materiales granulares en las secciones de la Instrucción 6.1 y 6.2 IC

[Resumen:] En el presente trabajo, se van a comprobar las secciones de la Instrucción de Carreteras (6.1 y 2 IC) que incorporen en su estructura capas de materiales granulares. Sin embargo, en esta oportunidad, en vez de emplear como herramienta de cálculo un sistema multicapa se utilizarán dos modelos numéricos para estudiar la respuesta de estas capas granulares: un modelo tridimensional (en FLAC3D), empleando un esquema explícito de diferencias finitas, y un modelo axilsimétrico (en SIGMA/W), que trabaja con elementos finitos