Search results for "earth-surface processes"
showing 10 items of 1293 documents
Monitoring of stress distribution in damaged small-scale masonry walls by using two innovative sensors
2023
Structural Health Monitoring (SHM) represents a strategic solution for the preservation of cultural heritage buildings. Existing masonry structures often suffer reductions in mechanical performances due to physiological aging of material constituents, external actions, and effect of catastrophic natural events. In many cases, the prompt prediction of damage in masonry elements is difficult and it can cause sudden collapses, compromising the safety of people. The proposed experimental study examines the effectiveness of two low-cost and innovative stress sensors, i.e. piezoelectric and capacitive stress sensors, for SHM of masonry structures. To this scope, the sensors were embedded in the m…
Dynamique fluvial, changement global et pression anthropique dans le bassin, le cours et le delta de l'Ébre
2017
Le fonctionnement des rivières du bassin de l’Èbre a subi d’importants changements depuis 1950. Il s’agit d’un processus rapide et très marqué, de simplification et de stabilisation sur le fleuve principal et sur ses principaux affluents pyrénéens. Ce processus s’est manifesté par des changements dans la morphologie fluviale, le développement de la végétation sur les lits, un rétrécissement de l’espace naturel fluvial et une incision des lits fluviaux. Les facteurs de ce processus sont le changement global dans le bassin, la construction de réservoirs d’eau et d’autres nombreuses pressions humaines directes, notamment d’extractions de graviers et de canalisations. Le delta de l’Èbre, actuel…
In situ measurements of background aerosol and subvisible cirrus in the tropical tropopause region
2002
[1] In situ aerosol measurements were performed in the Indian Ocean Intertropical Convergence Zone (ITCZ) region during the Airborne Polar Experiment-Third European Stratospheric Experiment on Ozone (APE-THESEO) field campaign based in Mahe, Seychelles between 24 February and 6 March 1999. These are measurements of particle size distributions with a laser optical particle counter of the Forward Scattering Spectrometer Probe (FSSP)-300 type operated on the Russian M-55 high-altitude research aircraft Geophysica in the tropical upper troposphere and lower stratosphere up to altitudes of 21 km. On 24 and 27 February 1999, ultrathin layers of cirrus clouds were penetrated by Geophysica directly…
A New Spatial Shift‐Share Decomposition: An Application to Tourism Competitiveness in Italian Regions
2020
The paper proposes a new version of spatial shift-share decomposition to improve on the various approaches to conventional shift-share analysis found in the literature. The novelty of our proposal is that it enables researchers to assess spatial competitiveness effects controlling for the influence of industrial specialization at both regional and neighborhood level. This new version is applied to inbound tourism in Italian regions and enables us to identify the best and worst performers. Our empirical results identify favorable scenarios in some areas of the country, such as Sardinia as well as regional advantage in a sizeable number of well-known destinations.
Urban Flood Prediction through GIS-Based Dual-Coupled Hydraulic Models
2022
Propagation of pluvial floods in urban areas, occurring with return time periods of few years, can be well solved using dual models accounting for the mutual relationship between the water level in the streets and the discharges inside the sewer pipes. The extended WEC-flood model (EWEC), based on the use of unstructured triangular meshes and a diffusive formulation of the momentum equations in both the 2D and the 1D lower domains, is presented along with its novelty, limits, and advantages. The model is then applied to a small computational domain in the Palermo area, where only some ‘hard’ data given by one rain gauge has been used for calibration and validation, along with ot…
Geography of urban and locational conflicts in Valencia and its metropolitan area
2021
Aquest article fa una anàlisi sobre els conflictes territorials sorgits al llarg dels darrers anys, de principis de la dècada de 2000 fins a 2013, a l’àrea metropolitana de València. Amb aquesta anàlisi, volem realitzar una radiografia sobre la conflictivitat territorial d’aquest espai urbà i avançar hipòtesis amb referència a les causes que la van provocar, com també estudiar les connexions espacials que es van establir, de cara a una formulació posterior de recomanacions per a una planificació urbana i territorial i un govern de la ciutat millors. Aquest treball és el resultat d’una recerca sistemàtica sobre conflictes territorials, actors i estratègies en tota mena de disputes relacionad…
Holocene sea level change in Malta
2013
A multidisciplinary approach has been applied to study sea level changes along the coast of Malta using data collected from underwater archaeological remains. The elevation of archaeological markers have been compared with predicted sea level curves providing new bodies of evidence that outline the vertical tectonic behaviour of this region, allowing estimation of the relative sea level changes that occurred in this area of the Mediterranean since the Bronze Age. During the Roman Age, sea level was at −1.36 ± 0.1 m, while in the Midde Age it was at −0.56 ± 0.2 m, in agreement with previous estimations for the Mediterranean region. Data indicate that Malta was tectonically stable during the …
L’aire urbaine de Valencia dans le système global des villes : Les effets de la crise économique sur le réseau des liens financiers des entreprises m…
2021
El artículo analiza el impacto que la crisis económica ha tenido sobre las redes de relaciones de propiedad-filiación de las empresas multinacionales, consideradas en la literatura científica como uno de los factores más importantes en la integración de las ciudades en la globalización. El caso de estudio es el área metropolitana de Valencia, un centro de segundo nivel en las redes económicas mundiales que ha sido duramente golpeado por los efectos de la crisis desde 2008. A partir del análisis de bases de datos de empresas multinacionales en dos fechas de referencia, 2010 y 2013, se constata que la crisis económica ha provocado un retroceso en la inserción del área metropolitana en dichas …
Welded section defence by LRPD devices
2023
The present paper concerns a special application of some recently proposed structural devices, called LRPD, able to protect the welded sections of frame steel structures from undesired brittle collapse ensuring the good expected ductile behaviour. Standard I-shaped cross-sections are treated, and the proposed devices are suitably considered as moment resisting connections between beams and columns. At first the domain representing the brittle safe conditions is defined in the N,V,M space; then a sample plane frame subjected to seismic load conditions is studied and it is proved that, equipping the structure with the proposed devices suitably designed, the generalized stresses at the welded …
Late Jurassic (Kimmeridgian–Tithonian) stable isotopes (δ18O, δ13C) and Mg/Ca ratios: New palaeoclimate data from Helmsdale, northeast Scotland
2010
Abstract The data presented here provide the first detailed stable isotope ( δ 18 O, δ 13 C) and geochemical (Mg/Ca) investigation of Kimmeridgian–Tithonian belemnites from the Helmsdale Coast, Scotland, UK. Oxygen and carbon stable isotope values from well preserved specimens range from − 2.8 to + 0.3‰ and from − 2.3 to + 2.8‰ respectively. The oxygen isotope data are consistent with palaeotemperatures of up to 24 °C in the Early Kimmeridgian cymodoce Zone and down to 11 °C in the Mid Tithonian rotunda–fittoni Zones. These estimates are strongly supported by the Mg/Ca data, which also indicate a cooling episode (and very similar palaeotemperatures, 11–22 °C) at this time. The cooling event…