Search results for "Density"
showing 10 items of 4402 documents
Cognate xenoliths in Mt. Etna lavas: witnesses of the high-velocity body beneath the volcano
2013
Various xenoliths have been found in lavas of the 1763 (“La Montagnola”), 2001, and 2002–03 eruptions at Mt. Etna whose petrographic evidence and mineral chemistry exclude a mantle origin and clearly point to a cognate nature. Consequently, cognate xenoliths might represent a proxy to infer the nature of the high-velocity body (HVB) imaged beneath the volcano by seismic tomography. Petrography allows us to group the cognate xenoliths as follows: i) gabbros with amphibole and amphibole-bearing mela-gabbros, ii) olivine-bearing leuco-gabbros, iii) leuco-gabbros with amphibole, and iv) Plg-rich leuco gabbros. Geobarometry estimates the crystallization pressure of the cognate xenoliths between …
Predation risk and habitat selection of Australian house mice , Mus domesticus , during an incipient plague: desperate behaviour due to food depletion
2002
We studied habitat selection and foraging behaviour of the house mouse (Mus domesticus) related to increasing mouse densities and depleting food resources over the breeding season. The study was conducted during the increase phase of an incipient outbreak of mice in a grain-growing area of southeastern Australia. A 3-year rotation created a mosaic of large paddocks of grain crop, pasture, and fallow. The narrow fence lines between paddocks provide an important stable habitat for the mice. We monitored population densities with live-trapping and habitat preference by measuring giving-up densities (GUD) using artificial food patches. Food patches were established in crop fields, fence lines, …
Morphometric indices as indicators of tectonic, fluvial and karst processes in calcareous drainage basins, South Menorca Island, Spain
2007
This study proposes using morphometric indices to discriminate the processes that shape calcareous drainage basins. To illustrate this, a DEM of the southern part of Menorca Island (Migjorn) was created and basin slope, drainage density, hypsometric curve and integral, and the area occupied by open and closed dolines were extracted from it. These indices show an important dependence on tectonics, which govern the morphology of these drainage basins and encourage the predominance of karst and/or fluvial processes in the different sectors. The morphometric indices are clearly influenced by the geological Migjorn structure, a carbonate Upper Miocene reef platform gently folded as an asymmetric…
Pullout Force and Inlet Oscillation in Telescopic Carbon Nanotubes: A Quantum Study
2021
The noncovalent interaction energy as a function of the core extension in double-walled carbon nanotubes (DWCNT) was accurately calculated in the frame of density functional theory, considering dis...
Biogeographical comparison of winter bird assemblages in urban environments in Finland
1996
We studied biogeographical variation of urban bird assemblages in Finland. Winter birds were censused by single-visit study plot method from thirty-one centres of villages or towns along 950 km latitudinal extent. A total twenty-eight bird species was observed and the average density was 61.2 ind./10 ha. The number of dominant species in study areas varied between two and seven and their proportion of the whole assemblage was over 70%. Species richness, but not the density of birds, decreased northwards in pooled data. Higher species richness in south than in north was mainly due to the higher amount of delayed migratory birds (e.g. waterbirds, finches) and southerly distributed bird specie…
Rotifer vertical distributions in a meromictic basin of Lake Banyoles (Spain)
1993
The vertical distribution of rotifer populations has been analyzed in a meromictic basin (III) of the karstic Lake Banyoles. This basin had, at the time of the study, an anaerobic monimolimnion from around 17 m in summer or 21 in winter to 25 m, its maximum depth. However, below this layer a warmer micro aerophiliczone with suspended marls is found in a chimney to a depth of 130 m.
Growth of two-dimensional Au patches in graphene pores : a density-functional study
2016
Grafeenin löytämisen myötä kaksiulotteisten (2D) materiaalien tutkimus on edennyt huomattavasti viimeisen vuosikymmenen aikana. Myös 2D-metalleja on tutkittu, ja esimerkiksi atominpaksuinen rautakerros on onnistuttu kokeellisesti luomaan grafeenin reunalle. Metalleista erityisesti kullan on havaittu käyttäytyvän hyvin eri tavalla nanomittakaavassa. Tässä Pro gradu -tutkielmassa on simuloitu kaksiulotteisten kultasaarekkeiden kasvua grafeenin reunalle tiheysfunktionaaliteoriaa (DFT) käyttämällä. Tavoitteena oli selvittää, kuinka kulta-atomit kulkeutuvat grafeenin pintaa pitkin lopulta reunalle, ja asettuvatko kulta-atomit kaksiulotteisesti samaan tasoon grafeenin kanssa. Tulosten perusteella…
Search for anisotropic gravitational-wave backgrounds using data from Advanced LIGO and Advanced Virgo's first three observing runs
2021
We report results from searches for anisotropic stochastic gravitational-wave backgrounds using data from the first three observing runs of the Advanced LIGO and Advanced Virgo detectors. For the first time, we include Virgo data in our analysis and run our search with a new efficient pipeline called {\tt PyStoch} on data folded over one sidereal day. We use gravitational-wave radiometry (broadband and narrow band) to produce sky maps of stochastic gravitational-wave backgrounds and to search for gravitational waves from point sources. A spherical harmonic decomposition method is employed to look for gravitational-wave emission from spatially-extended sources. Neither technique found eviden…
Vitesse, accessibilité et étalement urbain ; analyse et application à l'aire urbaine dijonnaise
2003
The set of themes of the city is approached primarily by the means of the residential density. This concept is analyzed from a purely conceptual point of view, then more theoretical (thus making use of rather traditional econometric models: Clark, Newling) for finally being applied to the agglomeration dijonnaise like with its urban surface. One releases the great urban structures thus revealing an intermediate city between the model monocentric and polycentric. The two components are analyzed successively starting from the concept of residential density. Taking as assumption that the cities are dynamic, the second stage is that of urban sprawl out. A first introductory approach attempts to…
Escaping scaling relationships for water dissociation at interfacial sites of zirconia-supported Rh and Pt clusters
2019
<p>Water dissociation is an important reaction involved in many industrial processes and a good model reaction for probing the activity of catalytic sites. In this computational study, the dissociation of water at interfacial sites of globally optimized ZrO2 sup- ported Pt and Rh clusters is investigated under the framework of density functional theory. Our findings demonstrate that the perimeter sites of these small clusters can activate water, but the dissociation behavior varies considerably between sites. It is shown that the studied clusters break scaling relationships for water dissociation, suggesting these catalysts may achieve activities beyond the maximum imposed by such rel…