1,721,009 research outputs found
The vascular flora of the Lake Burano Nature Reserve (Grosseto, southern Tuscany, Italy) [La Flora vascolare della Riserva Naturale Lago di Burano (Grosseto, Toscane meridionale)]
No full textLake Burano is in Tuscany, near the border with Latium (Capalbio municipality, Grosseto province, Italy). The results of a survey of the flora of the Lake Burano Nature Reserve in the period 1995-99 are reported. Data from the literature and specimens collected in the early 1990s during mycological studies were also considered. The landforms, climate and vegetation of the area are described, followed by a list of vascular plants with explanatory notes on entities of phytogeographical and/or conservation interest. The list consists of 522 taxa with 492 spontaneous or naturalised plants, 10 recently introduced species and 20 species found in the literature but not confirmed in the field. Spontaneous flora belongs to 301 genera and 81 families. Entities of phytogeographical interest for Tuscany and often for Italy include: i) endemic species and species close to the limit of their distribution, such as Dorycnium rectum, Fumaria bicolor, Linaria purpurea subsp. cossoni, Polygonum romanum and Quercus frainetto; ii) psammophiles such as Crucianella maritima, Euphorbia paralias, Medicago marina, Matthiola sinuata and Stachys maritima, most of which are in the Tuscan list of threatened species; iii) rare species and species with fragmented distribution linked to wet areas (salt and freshwater), such as Aeluropus littoralis, Artemisia coerulescens var. palmata, Carex ext ens a, C. riparia, Cladium mariscus, Eleocharis uniglumis, Euphorbia palustris, Halimione portulacoides, Hydrocotyle vulgaris, Orchis palustris, Plantago cornuti, Ranunculus sceleratus, Spartina juncea, Spirodela polyrrhiza and Stachys palustris. The data show that many years of protection have made the reserve one of the best conserved sectors of the Tuscan coast, with regard to flora
Grasslands of the order Brometalia erecti Br.-Bl. 1936 on Antiapennine calcareous massifs in central-southern Tuscany (central Italy)
No full textFloristic characteristics, syntaxonomy and synecology of grasslands of the order Brometalia erecti on calcareous massifs of central-southern Tuscany are reported. Multivariate analysis was used to compare 64 phytosociological relevés made in the years 1997, 2000 and 2001. These pastures occur in areas of the temperate oceanic region, with upper hill to montane thermotype and lower humid to lower hyperhumid ombrotype, in serial contact with woods of Ostrya carpinifolia Scop. and with beech woods on summits. The plant communities surveyed were classified in the following associations: i) Cerastio etrusci-Brometum erecti ass. nova (Phleo-Bromion Biondi and Blasi ex Biondi and al. 1995), identified for xeric grasslands on moderate to steep slopes with basic lithosols in the hill and lower montane belts; it has two variants related to soil chemical and physical characters; comparison with similar vegetation of other Apennine areas confirms the western connotation and autonomous nature of these communities; ii) Trifolio incarnati-Brometum erecti Oberdorfer and Hofmann 1967 (Bromion W. Koch 1926), known from the Ligurian Apennine downwards; in the area studied it shows a new «Antiapenninic» subassociation named phleetosum ambigui that includes: a mesophilous variant with Arrhenatherum elatius, related to flat or north-exposed stations in the mountain belt linked to mature soils with high moisture all year, rich in transgressive species of the class Molinio-Arrhenatheretea Tüxen 1937; a subnitrophilous variant with Carlina corymbosa, related to grazing and exclusive to soils with high clay component; a transition variant towards xerophilous grasslands. The study confirms the presence of the alliance Phleo-Bromion in Tuscany as an isolated appendage with northern outposts of xerocalcicolous communities widespread in the central-southern Apennine; a similarity with vegetation of northern Tyrrhenian sectors was also observed
Thermal and microchemical characterisations of CaSO4-SiO2 investment materials for casting jewellery alloys
No full textDifferential thermal analysis (DTA) and thermogravimetry (TG), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS) were used to study the thermal decomposition of calcium sulphate in the CaSO4 (25 wt%)-bonded silica investment which is the commonly used material for casting jewellery gold-based alloys. The thermal decomposition of CaSO4 generates sulphur dioxide, leads to gas porosity in the molten gold-based alloys and therefore, defective jewellery products. This latter reaction was studied as a function of the temperature and atmosphere (air, argon and argon-5% hydrogen). in order to simulate, as for as possible, different casting conditions used by the jewellery industry. Furthermore, special attention was given to the effect of the presence of Zn, Cu2O. CuO and Ag2O on the thermal decomposition of CaSO4. DTG-TG results confirmed that the temperature of the thermal decomposition of CaSO4 bonded with silica was lower with respect to the nearly pure CaSO4. Unfortunately, it was very close to the casting temperature of some typical gold alloys. in addition, the temperature of the decomposition was further lowered when inert and reducing atmospheres are used, as well as in the presence of ZnO, Cu2O. CuO and Ag2O. (C) 1998 Elsevier Science B.V
The Smart Project – Speed measurement validation in real traffic condition
No full textIn this paper an automatic validation system for
speed measurement devices is described. The system was
specifically designed to test speed within the SMART Project, an experimental survey on traffic monitoring devices led by ANAS, the Italian Road Agency. A matrix of infrared sensors
was used to implement the system and allow accurate speed measurements under real traffic condition, without road restraints. Special reflecting devices were developed in order to separate single lane measurements and reveal vehicles crossing among them. A GPS in-vehicle speed measurement device with
high accuracy was used to test and validate the system
Il ripostiglio della tenuta di Lunghezzina (Roma), 1995; indagine microchimica e microstrutturale
No full textVascular flora of "Bosco Rocconi" WWF Oasis (Grosseto, Southern Tuscany) [Flora vascolare dell'Oasi WWF "Bosco Rocconi" (Grosseto, Toscana meridionale)]
No full textWe report the results of floristic research carried out in the "Bosco Rocconi" WWF Oasis. Firstly, a brief description of the geomorphological, climatical and vegetational features of the area is given. Secondly, the list of the vascular flora is given, which was made out through floristic field researches, bibliography and herbarium specimens. This list includes 548 species belonging to 88 families and to 362 genera; only 6 of them are introduced species. The biological spectrum shows that hemicryptophytes outnumber therophytes here - 39,4% against 28,1% - suggesting a mixture of subcontinental and mediterranean subclimate. This is also confirmed by the chorological analysis, which reveals an equal distribution of Mediterranean and Eurosiberian elements and numerous connections with the oroipsophylous subdominion. There are three endemic species (Cerastium arvense subsp. arvense var. etruscum, Leontodon rosani and Ornithogalum etruscum). Moreover, a number of species are interesting from a phytogeographical and conservational viewpoint: Biscutella cichoriifolia, Dictamnus albus, Cardamine monteluccii, Euphorbia pterococca, Linum nodiflorum, Ruscus hypoglossum, Santolina etrusca. The data collected indicate that the Oasis is a key area for the protection of many calcicolous xerophytes. Moreover, its environmental variety allows a fairly high level of floristic biodiversity. © 2018 Società Botanica Italiana onlus
Production of reference ancient Cu-based alloys and their accelerated degradation methods
No full text
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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