Search results for "Tributi"
showing 10 items of 6415 documents
Występowanie Ricciocarpos natans (Marchantiophyta) na Śląsku
2017
The occurrence of Ricciocarpos natans (L.) Corda in Silesia (SW Poland) is discussed in its geographical and phytosociological aspects. The paper lists localities of this species and indicates its occurrence in plant communities, with special attention to Ricciocarpetum natantis an association rare and threatened in Poland. Ricciocarpos natans is a fairly common species in Silesia, known from 70 stations. Patches of Ricciocarpetum natantis are documented from 11 localities.
PICOPHYTOPLANKTON DYNAMICS IN NOISY MARINE ENVIRONMENT
2012
We present a stochastic reaction-diffusion-taxis model to describe the picophytoplankton dynamics along a water column. The model, which is valid for poorly mixed waters, typical of the Mediterranean Sea, considers intraspecific competition of picophytoplankton for light and nutrients. Random fluctuations of environmental variables are taken into account by adding a source of multiplicative noise to the diffusion equation for the picophytoplankton biomass concentration, whose distribution along the water column shows a maximum at a certain depth. After converting our results into chlorophyll a concentrations, we compare theoretical distributions, obtained for different noise intensities, wi…
The Influence of Contextual Aspects in Talent Development: Interaction Between Relative Age and Birthplace Effects in NBA-Drafted Players
2021
The aims of this study were two-fold: (1) to inspect separately for the relative age and birthplace effects for players selected in the National Basketball Association (NBA) draft; (2) to explore the interaction among these factors and analyse this interaction in players' career performance. The database was obtained from the official records of the players (n = 1,738), who were selected during the annual editions of the NBA Draft from 1990 to 2019. The participants' date of birth was analyzed according to the month of birth and divided into four quartiles. The place of birth was compared to the distribution of the general population' places of birth based on different communities' sizes. C…
Aportaciones sobre la corología y estado de conservación de algunas plantas raras y amenazadas del macizo del Penyagolosa
2019
Se comunican nuevas localidades, o se precisa la ubicación de antiguas citas, de diversas plantas vasculares consideradas raras o amenazadas en el conjunto de la flora del Macizo del Penyagolosa, la mayoría presentes en el municipio de Vistabella del Maestrat (Castellón). Se aportan datos poblacionales de algunas especies amenazadas para contribuir al seguimiento de su estado de conservación. The presence of new localities of various taxa of vascular plants is reported, which are considered rare or endangered for the flora of the Penyagolosa, mainly from Vistabella del Maestrat (Castellón). Population data of some endangered species are included to contribute to the monitoring of their cons…
Plate-forme contre canal : quel cadre théorique pour analyser la distribution ?
2019
Traditional retailers are facing the competition of new actors born in the internet world. Whereas those physical retailers try to expand online, the virtual operators recognize the need to develop a physical presence in the marketplace. Models of marketing channels are used to implement distribution strategies in physical stores, and the concept of multisided platform is now classically referred to for internet operations. How can those diverging theoretical frames be combined to help managers in their strategic decisions ?
Deep and Proximate Determinants of the World Income Distribution
2019
This paper studies the deep and proximate determinants of the evolution of the cross-country distribution of GDP per worker in the period 1960–2008 by a novel method based on an information criterion. We find that countries of our sample follow three distinctive growth regimes identified by two deep determinants, namely life expectancy at birth in 1960 and the share of Catholics in 1965, and that each regime is characterized by non-linearities. Growth regimes appear to be the main cause of the increased inequality and polarization, while technological catch-up, proxied by the initial level of GDP per worker, acts in the opposite direction. Finally, human capital marginally reduces polarizat…
Orbital angular momentum parton distributions in quark models
1999
At the low energy, {\sl hadronic}, scale we calculate Orbital Angular Momentum (OAM) twist-two parton distributions for the relativistic MIT bag model and for non-relativistic quark models. We reach the scale of the data by leading order evolution in perturbative QCD. We confirm that the contribution of quarks and gluons OAM to the nucleon spin grows with $Q^2$, and it can be relevant at the experimental scale, even if it is negligible at the hadronic scale, irrespective of the model used. The sign and shape of the quark OAM distribution at high $Q^2$ may depend strongly on the relative size of the OAM and spin distributions at the hadronic scale. Sizeable quark OAM distributions at the had…
Raman Investigations to Identify Corallium rubrum in Iron Age Jewelry and Ornaments
2016
International audience; During the Central European Iron Age, more specifically between 600 and 100 BC, red precious corals (Corallium rubrum) became very popular in many regions, often associated with the so-called (early) Celts. Red corals are ideally suited to investigate several key questions of Iron Age research, like trade patterns or social and economic structures. While it is fairly easy to distinguish modern C. rubrum from bone, ivory or shells, archaeologists are confronted with ancient, hence altered, artifacts. Due to ageing processes, archaeological corals lose their intensive red color and shiny surface and can easily be confused with these other light colored materials. We pr…
Titanium and Vanadium Catalysts with 2-Hydroxyphenyloxazoline and Oxazine Ligands for Ethylene-Norbornene (co)Polymerization
2019
A series of titanium and vanadium complexes with oxazoline 2-(4,5-dihydro-1,3-oxazol-2-yl)phenol (L1), 2-(4-methyl-4,5-dihydro-1,3-oxazol-2-yl)phenol (L2), and oxazine 2-(5,6-dihydro-4H-1,3-oxazin-2-yl)phenol (L3) ligands were synthesized, and their structures were determined by NMR and MS methods as (L)2MtCl2. The vanadium complexes were found to be highly active in ethylene (7300 kgPE/(molV·
A supported titanium postmetallocene catalyst: Effect of selected conditions on ethylene polymerization
2011
Ethylene polymerization with a titanium complex [N,N-ethylenebis(3-methoxysalicylideneiminato)titanium dichloride] immobilized on the magnesium support with the formula MgCl2(THF)0.32(Et2AlCl)0.36 was studied. In particular, the effects of polymerization temperature, monomer pressure, and polymerization time on the activity of the catalyst and on the polyethylene properties (molecular weight and its distribution, melting point, crystallinity, and bulk density) were evaluated. The findings of investigations prove that the studied supported titanium catalyst is highly active in ethylene polymerization, and its activity increases with increasing temperature and monomer pressure. Moreover, stab…