Search results for "BUDGET"
showing 10 items of 255 documents
Geochemical comparison of natural and anthropogenic metal fluxes in extreme environments: Mt. Etna volcano (Italy) and Šalek Valley (Slovenia)
2009
Geochemical comparison between some metals (As, Cd, Cu, Pb, Se, V, Zn) emissions from an active volcano (Mt. Etna) and a highly industrialized area (Šalek Valley) showed some interesting similarities: in general, most of the elements emitted into the atmosphere do not return to the Earth’s surface and are therefore dispersed into the environment. Exceptions for Šalek Valley are Cd, which probably derives in large part from rock leaching, and in part As and Pb, which fall mostly as ash. Also, Etna’s emissions are richer in Cd and Cu, whereas industrial emissions at Šalek Valley are richer in V and Zn. All other metals have similar fluxes in the two types of emissions.
The Influence of Trace Substances on the Atmospheric Energy Budget
1979
ABSTRACT The most effective absorbers of solar radiation in the system earth-atmosphere are the earth's surface layer, the atmospheric water vapor, ozone and oxygen. In the troposphere water vapor is dominant, in the lower stratosphere ozone. The absorption contribution due to carbon dioxide may be neglected in both regions of the atmosphere. The contribution of aerosol particles is significant only close to the earth's surface. Here the absorption by aerosol particles equals the effect by water vapor. This fact and the following properties of aerosol particles motivate a special treatment. Particles absorb; particles scatter and elongate the optical path of solar radiation through the abso…
Dynamics of sediments along with their core properties in the Monastir-Bekalta coastline (Tunisia, Central Mediterranean)
2017
International audience; The authors report on two campaigns of high-resolution samplings along the shores of Monastir Bay in Tunisia: the first being a study of sediment dynamics, grain size and mineral composition in surface sediment, and the second, eight months later, using four sediment cores to study grain-size distribution in bottom sediments. Particle size analysis of superficial sediment shows that the sand in shallow depths is characterized by S-shaped curves, indicating a certain degree of agitation, possible transport by rip currents near the bottom and hyperbolic curves illustrating heterogeneity of sand stock. The sediments settle in a relatively calm environment. Along the bay…
VALUTAZIONE DELLE PERFORMANCE E ATTIVITÀ DI INDIRIZZO, MONITORAGGIO E CONTROLLO SULLA PROGRAMMAZIONE PUBBLICA REGIONALE DEI FONDI STRUTTURALI. APPROC…
2014
La programmazione pubblica regionale attraversa un momento di forte criticità interna legata al soggetto attuatore regionale, caratterizzata da una lentissima attuazione dei programmi operativi cofinanziati dalla Commissione Europea. In risposta alle emergenze economiche e sociali, l’amministrazione regionale necessita di strumenti in grado di comunicare efficacemente azioni e risultati che possono positivamente influenzare la vita sociale e civile della comunità regionale. In particolare, gli operatori economici e, in generale, tutti i portatori di interesse, basano i propri atteggiamenti e le proprie scelte sulle aspettative delle dinamiche attese nei settori economici e sociali in cui op…
On the projected increase of Sahel rainfall during the late rainy season
2016
Thirteen CMIP5 models are used to analyse changes in climate over the West African monsoon region between the near future (2031–2070 under the RCP4.5 emission scenario), and a control period (1960–1999 under the historical emission scenario), with a focus on the late rainy season. The monsoon circulation is projected to strengthen and to shift northward leading to more rainfall during the Sahelian season. The results show an increase of the Rainfall amounts in September–October and a delay in the monsoon withdrawal. The increased moisture that fuels the rainfall anomalies is associated with an increase in moisture flux convergence and with local moisture recycling. The moisture transport do…
Modelling biogeochemical processes in sediments from the north-western Adriatic Sea: response to enhanced particulate organic carbon fluxes
2018
This work presents the result of a study carried out in the north-western Adriatic Sea, by combining two different types of biogeochemical models with field sampling efforts. A longline mussel farm was taken as a local source of perturbation to the natural particulate organic carbon (POC) downward flux. This flux was first quantified by means of a pelagic model of POC deposition coupled to sediment trap data, and its effects on sediment bioirrigation capacity and organic matter (OM) degradation pathways were investigated constraining an early diagenesis model by using original data collected in sediment porewater. The measurements were performed at stations located inside and outside the ar…
Scheduling independent stochastic tasks under deadline and budget constraints
2018
This article discusses scheduling strategies for the problem of maximizing the expected number of tasks that can be executed on a cloud platform within a given budget and under a deadline constraint. The execution times of tasks follow independent and identically distributed probability laws. The main questions are how many processors to enroll and whether and when to interrupt tasks that have been executing for some time. We provide complexity results and an asymptotically optimal strategy for the problem instance with discrete probability distributions and without deadline. We extend the latter strategy for the general case with continuous distributions and a deadline and we design an ef…
Distribution models and environmental changes : Application to echinoid faunas in the Southern Ocean and ecoregionalization
2018
Current environmental changes, which impact marine environments, cover major scientific and societal issues, especially as these environmental changes are expected to accelerate along the 21st century. Understanding and forecasting the response of marine biodiversity to these changes is a pregnant scientific issue. Biogeographic and macroecological approaches provide a scientific framework for that purpose. They allow describing and understanding species distribution patterns at large spatial scale as well as estimating their potential shift with regards to environmental change. This is particularly true in the Southern Ocean, where the effects of climate change are already occurring and wh…
Where Alonso meets Sierpinski: an urban economic model of a fractal metropolitan area
2004
International audience; La coexistence d'activités résidentielles et agricoles dans des ceintures périurbaines caractérise de nombreuses aires métropolitaines modernes. Malheureusement, peu de modèles théoriques de l'économie urbaine prennent en compte ce type de mixité spatiale. L'article contribue à combler cette lacune : les auteurs présentent un modèle de localisation résidentielle (standard en économie urbaine) opérant dans un espace structuré par la géométrie spatiale. Plus précisément, d'un côté, un tapis de Sierpinski est utilisé pour rendre compte de l'organisation hiérarchisée de sites urbains et ruraux dans une aire métropolitaine. D'un autre côté, un ménage maximise, sous contra…
Erosion des sols du Cap Vert : processus et quantification à l'échelle de trois Bassins Versants de l'île de Santiago
2010
The archipelago of Cape Verde comprises 10 volcanic islands and belongs to the Sahelian zone stretching from the Atlantic to the Red Sea. Since several decades, Cape Verde is affected by desertification caused largely by climatic recession and soil erosion. These factors, coupled with high population pressure on resources, rugged topography and torrential tropical rains, cause serious losses of lands. However, since its independence in 1975, the Government conducted an extensive program of afforestation, soil and water conservation. Nevertheless very little research has been conducted to evaluate the actions of protection and conservation of soil and water. Therefore, there is no data on th…