270 research outputs found
Evaluating hydrological and socio-economic impacts of green/blue space projects for storm water management = Evaluation des effets hydrologiques et socioéconomiques des espaces verts/bleus pour la gestion des eaux de pluie
FR: Les régions et villes européennes doivent faire face à des nombreuses questions liées à l'eau :gestion des eaux pluviales, qualité de l'eau, impact des sécheresses sur les milieux aquatiques. Pourrépondre durablement à ces questions, il est évident que l'eau doit être intégrée dans ledéveloppement urbain et dans les politiques d'aménagement du territoire. L'objectif général du projetpour la coopération interrégionale Aqua-Add (Mieux intégrer l'eau dans les projets urbains) est dedéployer le potentiel de l'eau dans les paysages urbains (potentiel économique, social etenvironnemental). Dans ce contexte, l'approche hydrologique et un modèle hédonique des prix sontintégrés et appliqués afin de vérifier les effets hydrologiques et socio-économiques des différentessolutions pour la gestion des eaux de pluie, et de faciliter le débat avec les acteurs de l'aménagement.L'objectif de cette étude est d'évaluer les effets hydrologiques et socio-économiques des espacesverts/bleus pour la gestion des eaux de pluie dans les villes moyennes. Nous présentons et étudionsici plus particulièrement l'étude de cas de Imperia (Italie)European regions and cities face important challenges related to water management, includingstorage, discharge, quality and periodic stress. To address these challenges, it is evident that watermust become an integral part of urban planning policies and their implementation. The internationalco-operation project Aqua-Add (Deploying the added value of water in local and regionaldevelopment) aims to deploy the potential of 'water' (economically, socially and environmentally) inurbanized landscapes and to improve the implementation of water measures in local and regionalurban planning. In this framework, hydrologic and hedonic-pricing simulation modelling approachesare integrated and applied in order to demonstrate the potential environmental, social and economicimpacts of different water management scenarios as well as to facilitate more informed decisionmaking across stakeholders. The objective of this paper is to assess the hydrological as well as socioeconomic implications of green/blue space projects for storm water management in medium-sizedcities. In particular, the case study of Imperia (Italy) is here presented and discussed
Thermal effects on atomic friction
We model friction acting on the tip of an atomic force microscope as it is
dragged across a surface at non-zero temperatures. We find that stick-slip
motion occurs and that the average frictional force follows ,
where is the tip velocity. This compares well to recent experimental work
(Gnecco et al, PRL 84, 1172), permitting the quantitative extraction of all
microscopic parameters. We calculate the scaled form of the average frictional
force's dependence on both temperature and tip speed as well as the form of the
friction-force distribution function.Comment: Accepted for publication, Physical Review Letter
Équilibrer les impacts sociaux et économiques des solutions écologiques pour la gestion des eaux pluviales
Early and Middle Holocene Hunter-Gatherer Occupations in Western Amazonia: The Hidden Shell Middens
We report on previously unknown early archaeological sites in the Bolivian lowlands, demonstrating for the first time early and middle Holocene human presence in western Amazonia. Multidisciplinary research in forest islands situated in seasonally-inundated savannahs has revealed stratified shell middens produced by human foragers as early as 10,000 years ago, making them the oldest archaeological sites in the region. The absence of stone resources and partial burial by recent alluvial sediments has meant that these kinds of deposits have, until now, remained unidentified. We conducted core sampling, archaeological excavations and an interdisciplinary study of the stratigraphy and recovered materials from three shell midden mounds. Based on multiple lines of evidence, including radiocarbon dating, sedimentary proxies (elements, steroids and black carbon), micromorphology and faunal analysis, we demonstrate the anthropogenic origin and antiquity of these sites. In a tropical and geomorphologically active landscape often considered challenging both for early human occupation and for the preservation of hunter-gatherer sites, the newly discovered shell middens provide evidence for early to middle Holocene occupation and illustrate the potential for identifying and interpreting early open-air archaeological sites in western Amazonia. The existence of early hunter-gatherer sites in the Bolivian lowlands sheds new light on the region's past and offers a new context within which the late Holocene "Earthmovers" of the Llanos de Moxos could have emerged. © 2013 Lombardo et al
URCA!: scenari di cambiamento climatico, eventi pluviometrici di progetto e approccio partecipato per migliorare la resilienza urbana
Velocity tuning of friction with two trapped atoms
Our ability to control friction remains modest, as our understanding of the underlying microscopic processes is incomplete. Atomic force experiments have provided a wealth of results on the dependence of nanofriction on structure velocity and temperature but limitations in the dynamic range, time resolution, and control at the single-atom level have hampered a description from first principles. Here, using an ion-crystal system with single-atom, single-substrate-site spatial and single-slip temporal resolution we measure the friction force over nearly five orders of magnitude in velocity, and contiguously observe four distinct regimes, while controlling temperature and dissipation. We elucidate the interplay between thermal and structural lubricity for two coupled atoms, and provide a simple explanation in terms of the Peierls–Nabarro potential. This extensive control at the atomic scale enables fundamental studies of the interaction of many-atom surfaces, possibly into the quantum regime
On the Commonality Between Theoretical Models for Fluid and Solid Friction, Wear and Tribochemistry
Microstructural and topographic characterization of concrete protected by acrylic paint
A SOM-based Chan–Vese model for unsupervised image segmentation
Active Contour Models (ACMs) constitute an
efficient energy-based image segmentation framework. They usually deal with the segmentation problem as an optimization problem, formulated in terms of a suitable functional, constructed in such a way that its minimum is achieved in correspondence with a contour that is a close approximation of the actual object boundary. However, for existing ACMs, handling images that contain objects characterized by many different intensities still represents a challenge. In this paper, we propose a novel ACM that combines—in a global and unsupervised way—the advantages of the Self-Organizing Map (SOM) within the level set framework of a state-of-the-art unsupervised global ACM, the Chan–Vese (C–V) model. We term our proposed model SOM-based Chan– Vese (SOMCV) active contourmodel. It works by explicitly integrating the global information coming from the weights (prototypes) of the neurons in a trained SOM to help choosing whether to shrink or expand the current contour during the optimization process, which is performed in an iterative
way. The proposed model can handle images that contain
objects characterized by complex intensity distributions, and is at the same time robust to the additive noise. Experimental results show the high accuracy of the segmentation results obtained by the SOMCV model on several synthetic and real images, when compared to the Chan–Vese model and other image segmentation models
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