Search results for "Terre"
showing 10 items of 655 documents
Towards automated and operational forest inventories with T-Lidar
2011
International audience; Forest inventory automation has become a major issue in forestry. The complexity of the segmentation of 3D point cloud is due to mutual occlusion between trees, other vegetation, or branches. That is why, the applications done until now are limited to the estimation of the DBH (Diameter at Breast Height), the tree height and density estimation. Furthermore other parameters could also be detected, such as volume or species of trees (Reulke and Haala) . . . This paper presents an effective approach for automatic detection, isolation of trees and DBH estimation. Tree isolation is achieved using an innovative approach based on a clustering methodology followed by a skele…
Excitons in few-layer hexagonal boron nitride: Davydov splitting and surface localization
2018
Hexagonal boron nitride (hBN) has been attracting great attention because of its strong excitonic effects. Taking into account few-layer systems, we investigate theoretically the effects of the number of layers on quasiparticle energies, absorption spectra, and excitonic states, placing particular focus on the Davydov splitting of the lowest bound excitons. We describe how the inter-layer interaction as well as the variation in electronic screening as a function of layer number $N$ affects the electronic and optical properties. Using both \textit{ab initio} simulations and a tight-binding model for an effective Hamiltonian describing the excitons, we characterize in detail the symmetry of t…
Time-dependent screening explains the ultrafast excitonic signal rise in 2D semiconductors
2020
We calculate the time evolution of the transient reflection signal in an MoS$_2$ monolayer on a SiO$_2$/Si substrate using first-principles out-of-equilibrium real-time methods. Our simulations provide a simple and intuitive physical picture for the delayed, yet ultrafast, evolution of the signal whose rise time depends on the excess energy of the pump laser: at laser energies above the A- and B-exciton, the pump pulse excites electrons and holes far away from the K valleys in the first Brillouin zone. Electron-phonon and hole-phonon scattering lead to a gradual relaxation of the carriers towards small $\textit{Active Excitonic Regions}$ around K, enhancing the dielectric screening. The acc…
Nuevos fármacos inspirados en Annonáceas
2014
Los metabolitos secundarios activos (MSA) juegan un papel importante en el descubrimiento de nuevos medicamentos. Moléculas naturales con esqueletos complejos, tales como las estatinas aisladas de Aspergillus terreus, o las acetogeninas específicas de la familia Annonaceae, no hubieran podido ser inventadas en ningún laboratorio. Los MSA aislados en Annonaceae, especialmente las acetogeninas y los alcaloides isoquinoleínicos, pueden ser considerados como fuente constante de inspiración para químicos, farmacólogos y para todos los investigadores interesados en el descubrimiento de una nueva familia de medicamentos. Active secondary metabolites (ASM) play a highly significant role in the drug…
Ecology and extent of freshwater browning - What we know and what should be studied next in the context of global change
2022
Water browning or brownification refers to increasing water color, often related to increasing dissolved organic matter (DOM) and carbon (DOC) content in freshwaters. Browning has been recognized as a significant physicochemical phenomenon altering boreal lakes, but our understanding of its ecological consequences in different freshwater habitats and regions is limited. Here, we review the consequences of browning on different freshwater habitats, food webs and aquatic-terrestrial habitat coupling. We examine global trends of browning and DOM/DOC, and the use of remote sensing as a tool to investigate browning from local to global scales. Studies have focused on lakes and rivers while seldo…
The Church of S. Maria Delle Palate in Tusa (Messina, Italy): Digitization and Diagnostics for a New Model of Enjoyment
2022
Cultural places represent the tangible part of the identity and historical heritage of a civilization as well as an extraordinary driving force for the economic development of a country. Within its huge asset, Italy counts a wide number of archaeological sites and monuments which, despite their cultural value, are totally cut off from the most important cultural routes. This paper aims to demonstrate how specific actions of digitization can contribute to valorize (restoring a cultural value) ‘marginal’ landmarks, promoting their knowledge and inclusion. The case study described is represented by the Church of “Santa Maria delle Palate”, located inside the well-known …
LA RICOSTRUZIONE DIFFICILE: CONFLITTI SOCIALI E IMPRESE ARCHITETTONICHE NEL VAL DI NOTO DOPO IL TERREMOTO DEL 1693
2012
La storiografia riferita alle vicende post sismiche del Val di Noto ha ricorrentemente interpretato lo straordinario patrimonio architettonico realizzato dopo il terremoto del 1693 come il risultato di uno sforzo collettivo, che vide coinvolti in modo sinergico tutti i livelli della società siciliana. Il terremoto è stato insomma visto spesso come un evento traumatico capace di saldare – in una sorta di comune reazione della vita contro la morte – il governo spagnolo, la nobiltà feudale, il clero e le comunità urbane, queste ultime in una posizione subalterna rispetto alle determinazioni delle tre tradizionali sfere del potere Ancién Regime (Monarchia, Nobiltà e Chiesa).Il progredire degli …
ARCHITETTURA E ARTE CONTEMPORANEA NELLA VALLE DEL BELICE, IN SICILIA, COLPITA DAL SISMA DEL 1968: UN BILANCIO TRA ISTANZE DI CONSERVAZIONE E PROPOSTE…
2013
Because of the 1968 earthquake it was considered necessary thinking better of those years debate to rebuild Belice’s centres. In particular thanks to Gibellina’s experience we could appreciate the actuality of the union between contemporary art’s innovative charge and the damaged architectural estate, that was introduced for “the refounding”. This theory was about using the introduction of artworks into urban centers and public buildings as a resource’s “catalyst” to improve environmental quality. The Grande Cretto by Alberto Burri (1985) stretched out the Gibellina’s ruins included forever the dead city’s remains such as a shroud. Case Di Lorenzo museum (1981) contains the anastylosis of t…
Propagating Alfvén waves in open structures with random structuring
2022
Funding: The research leading to these results has received funding from the UK Science and Technology Facilities Council (consolidated grant ST/N000609/1), the European Union Horizon 2020 research and innovation programme (grant agreement No. 647214). IDM received funding from the Research Council of Norway through its Centres of Excellence scheme, project number 262622. We consider the behaviour of Alfvén waves propagating in a medium with random density perturbations. The imposed density perturbations have a broadband spectrum and their characteristic spatial scale may be defined according to the peak in the spectrum. The interaction of the boundary driven Alfvén waves with the medium ge…
L'origine de toutes les altérations superficielles du tubercule de pomme de terre est-elle vraiment infectieuse?
2009
SPE communication orale, résumé; Deux essais en sol stérile testant le pouvoir pathogène des souches le plus fréquemment isolées et inoculées seules, et un essai en hydroponie testant l'effet de co-inoculations de 2 souches sur l'apparition des altérations ont été mis en place.