Search results for "FOREST"
showing 10 items of 3780 documents
Sources, size distribution, and downwind grounding of aerosols from Mount Etna
2006
The number concentrations and size distributions of aerosol particles >0.3 mm diameter were measured at the summit of Mount Etna and up to 10 km downwind from the degassing vents during July and August 2004. Aerosol number concentrations reached in excess of 9 106 L1 at summit vents, compared to 4–8 104 L1 in background air. Number concentrations of intermediate size particles were higher in emissions from the Northeast crater compared to other summit crater vents, and chemical composition measurements showed that Northeast crater aerosols contained a higher mineral cation content compared to those from Voragine or Bocca Nuova, attributed to Strombolian or gas puffing activity within the ve…
Spirit Mars Rover Mission to the Columbia Hills, Gusev Crater: Mission overview and selected results from the Cumberland Ridge to Home Plate
2008
This paper summarizes the Spirit rover operations in the Columbia Hills of Gusev Crater from sols 513 to 1476 and provides an overview of selected findings that focus on synergistic use of the Athena Payload and comparisons to orbital data. Results include discovery of outcrops (Voltaire) on Husband Hill that are interpreted to be altered impact melt deposits that incorporated local materials during emplacement. Evidence for extensive volcanic activity and aqueous alteration in the Inner Basin is also detailed, including discovery and characterization of accretionary lapilli and formation of sulfate, silica, and hematite-rich deposits. Use of Spirit's data to understand the range of spectra…
Modeling suggests that oblique extension facilitates rifting and continental break-up
2012
[1] In many cases the initial stage of continental break-up was and is associated with oblique rifting. That includes break-up in the Southern and Equatorial Atlantic, separation from eastern and western Gondwana as well as many recent rift systems, like Gulf of California, Ethiopia Rift and Dead Sea fault. Using a simple analytic mechanical model and advanced numerical, thermomechanical modeling techniques we investigate the influence of oblique extension on the required tectonic force in a three-dimensional setting. While magmatic processes have been already suggested to affect rift evolution, we show that additional mechanisms emerge due to the three-dimensionality of an extensional syst…
Numerical analysis of ionosphere disturbances and Schumann mode splitting in the Earth-ionosphere cavity
2008
[1] The variability of ionosphere properties plays an important role in the Schumann resonances (SR), amplitudes, frequencies, and Q factor. Therefore, as atmosphere ionization is related to solar activity, SR could be devised as a source of indirect parameters that locally from the surface of the Earth could provide space weather information. A proper understanding of this link to SR parameters can be obtained through finite difference time domain (FDTD) simulations, specifically with the numerically obtained modes and frequencies that relate frequency shifts to the day-night asymmetry and polar inhomogeneities. Day-Night asymmetry is observed to have a minor influence in SR; however, larg…
Weed communities of root crops in the Pamir Alai Mts, Tajikistan (Middle Asia)
2013
<p>The paper presents the results of investigations of weed vegetation conducted on root crops in Tajikistan (Middle Asia), one of the world cradles of weed flora. The main research was conducted in the Zeravshanian, southern Tajikistan and Hissar-Darvasian geobotanical regions in 2011. The study was based on 107 phytosociological relevés obtained in various geobotanical regions of the country. The collected material probably presents the majority of variations among the weed communities of root cultivations in the Middle Asia. As a result of numerical analyses, 7 associations were distinguished: <em>Convolvulo arvensis-Cyperetum rotundi</em>, <em>Daturo stramonii-Hi…
Laukkopība
1939
Saturs (nodaļas): Priekšvārdi. Laukkopības būtība un laukkopības zinātnes uzdevumi. I. Augu augšanas faktori un to kārtošana laukā. I I . Augsnas auglība un ražība. III. Nezāles un to apkarošana. IV. Augsnas strādāšana. V. Lauku iedalīšana. VI. Eksperimentālā laukkopība (lauku izmēģinājumi). Literatūra. Lietu saraksts.
Machine Learning VS Transfer Learning - Smart Camera Implementation for Face Authentication
2018
The aim of this paper is to highlight differences between classical machine learning and transfer learning applied to low cost real-time face authentication. Furthermore, in an access control context, the size of biometric data should be minimized so it can be stored on a remote personal media. These constraints have led us to compare only lightest versions of these algorithms. Transfer learning applied on Mobilenet v1 raises to 85% of accuracy, for a 457Ko model, with 3680s and 1.43s for training and prediction tasks. In comparison, the fastest integrated method (Random Forest) shows accuracy up to 90% for a 7,9Ko model, with a fifth of a second to be trained and a hundred of microseconds …
Conservation of genetic diversity in artificially regenerated holm oak (Quercus ilex L.) populations
2004
Reforestation with autochtonous species should take into account the preservation of the variability and the geographical structure of genetic diversity in forest species. In order to provide empirical data, genetic composition of an artificial population of holm oak (Quercus ilex L.) and its natural seed-origin population in Andalusia were analysed with six microsatellite loci. The genetic diversity indices applied show a reduction in the artificial stand if compared with the natural one, probably due to an inappropriate forester seed collection strategy limited to a few trees.
Across and Within-Forest Effects on Breeding Success in Mediterranean Great TitsParus major
2010
Forest type and habitat structure can have profound effects on different aspects of avian life histories. These effects may, however, strongly differ across and within forests that vary in vegetation composition and structure, especially when an ancient forest has been replaced by a new forest. To test for these differences in effect, we studied Great Tit Parus major life-history traits (280 first clutches) in two Mediterranean evergreen forests during 2005–07: an ancient Holm Oak Quercus ilex and a reforested pine forest. A comparison between forests revealed that females breeding in the Holm Oak forest started laying one week later, and produced larger clutches and broods both at hatching…
Laying date and clutch size of Great Tits(Parus major) in the Mediterranean region: a comparison of four habitat types
1998
Laying data and clutch size of Great Tits were studied in four different habitats in eastern Spain: two holm oak(Quercus ilex) forests, at 500 and 900–950 m a.s.l., a zeen oak(Quercus faginea) forest, at 900–1100 m a.s.l., a pine(Pinus sylvestris) forest, at 1000–1050 m a.s.l., and orange(Citrus aurantium) plantations, at 30 m a.s.l. All sites were placed at about the same latitude (39–41°N), and all were studied during the same years (1992–95). Our results show that (1) laying date did not differ between the natural habitats at the same altitude (range of the means of yearly means 4–8 May); (2) within the same habitat type (holm oak forest) laying date was earlier at low altitude (30 April…