Search results for "solai"
showing 10 items of 19 documents
Timing and patterns of the ENSO signal in Africa over the last 30 years: insights from normalized difference vegetation index data.
2014
Abstract A more complete picture of the timing and patterns of the ENSO signal during the seasonal cycle for the whole of Africa over the three last decades is provided using the normalized difference vegetation index (NDVI). Indeed, NDVI has a higher spatial resolution and is more frequently updated than in situ climate databases, and highlights the impact of ENSO on vegetation dynamics as a combined result of ENSO on rainfall, solar radiation, and temperature. The month-by-month NDVI–Niño-3.4 correlation patterns evolve as follows. From July to September, negative correlations are observed over the Sahel, the Gulf of Guinea coast, and regions from the northern Democratic Republic of Congo…
Cycles diurnes de rayonnement solaire et forets en Afrique Centrale.
2018
The sunlightconditions prevailing in Central Africa, and their potential impact on forests traits and functioning, have neverbeen fully explored. Using satellite estimates documenting mostly the period 2005-2013, and accounting forscale interactions between the diurnal and annual cycles, we demonstrate that the seasonality of sunlight levelsstrongly vary across Central Africa forests. Gabon stands out with a main dry season strongly light-deficient,cool and moist. An original map of terra firme forest types developed by CIRAD shows that most of theevergreen forests of Central Africa develop in Gabon. We postulate that despite a mean annual precipitationamount below 2000 mm/yr, the Gabonese …
Solai ad orditura metallica. Per una storia della costruzione
2016
Sommario: Il saggio approfondisce gli aspetti storici e costruttivi dei solai ad orditura metallica dalla fine del XVIII secolo all’ultima guerra. Dopo una parte generale in cui vengono delineate le motivazioni e le fasi iniziali dell’uso dei materiali ferrosi in edilizia, si traccia ed analizza una serie di linee evolutive della trave metallica, fino al raggiungimento della sezione a doppio T che, a pieno titolo, si considera il punto di arrivo della ricerca sulla forma più conveniente per evidenti motivi di efficienza statica, pur coi successivi affinamenti nella produzione, nel calcolo e nella messa in opera. Si è ipotizzata l’evoluzione attraverso le strade della combinazione legno-ferr…
Solai con casseri in gesso
2008
Sonnenbarke und zyklisches Weltbild. Überlegungen zum Verständnis der spätbronzezeitlichen Ikonographie in Mitteleuropa
2005
International audience
Etude numérique du comportement thermique d’un séchoir solaire utilisant un lit thermique pour le stockage d’énergie
2018
This thesis presents a numerical study of an indirect natural convection solar dryer for drying agricultural products (Figs). The first part analyzes a solar dryer containing a drying chamber coupled to a reversed absorber and a solar chimney. Simulations were made to determine the dynamic and thermal fields under the influence of the variation of the solar chimney configuration and the size of the inlet opening. The governing equations based on the standard k-ε turbulence model are solved by the finite volume method using the ANSYS-Fluent commercial code. The second part analyzes the effect of adding a thermal storage in the form of a gravel bed in the drying chamber. The bed is modeled as…
CRITICAL REVIEW OF THE ARTICLE “DE BIBRACTE À AUGUSTODUNUM : OBSERVATIONS ARCHÉOASTRONOMIQUES”
2022
Were the towns of Bibracte and Augustodunum astronomically oriented? We study in this publication an article published in the Revue Archéologique de l'Est which puts forward the hypothesis that the Gallic town of Bibracte respects, in its main buildings, orientations corresponding to sunrise on the Romanized dates of the Celtic festivals and that the Roman city of Augustodunum is rather oriented, in its urban fabric, on sunrises at the solstice, like other Roman cities. Our study tends to invalidate these hypotheses, by re-examining the reliability of the measurements taken and the chronology of the constructions in relation to the establishment of the Julian calendar.
Estimation du rayonnement solaire dans le sud-ouest de l’océan Indien et a la Réunion : modélisation régionale du climat.
2014
6 pages; International audience; On analyse ici la capacité du modèle climatique régional RegCM4 à simuler les champs radiatifs, la températurede surface et les précipitations sur un domaine couvrant l’Afrique australe et le sud-ouest de l’océan Indien (0-40°S ; 0-100°E), centré sur La Réunion. Les données produites par le modèle sont confrontées aux données d’observations CERESpour les paramètres du rayonnement (ondes courtes et longues) et GPCP pour les précipitations, et aux données desréanalyses ERA-Interim pour la température. Six simulations ont été conduites, chacune avec un schéma de convectiondifférent, afin de tester la sensibilité des résultats à la physique du modèle.Le schéma m…
I principali riflessi del metodo semiprobabilistico agli stati limite nel progetto dei solai laterocementizi
2008
Travetti e solai
2005
L'articolo illustra le diverse tecniche di intervento per il recupero dei solai più diffusi nell'edilizia corrente, evidenziate da un'indagine comparativa sperimentale. Modelli, materiali ed esiti della ricerca.