1,257 research outputs found
L'attuazione dei regolamenti comunitari sull'imboschimento delle superfici agricole in Sicilia
No full text
Unihemispheric sleep and asymmetrical sleep: behavioral, neurophysiological, and functional perspectives [Corrigendum]
No full textMascetti GG. Nat Sci Sleep. 2016;8:221–38.For references 147, 153 and 154 the lead author should be Vyazovskiy, not Wyazovskiy.Read the original articl
LE IMPRESE OLIVICOLE ED OLEARIE IN SICILIA: VALUTAZIONE DEGLI ASPETTI ECONOMICI ED ORGANIZZATIVI
No full textIl comparto olivicolo-oleario rappresenta una risorsa importante dell''agricoltura della Regione Sicilia. Il presente lavoro analizza gli aspetti tecnico-economici dei nuovi modelli olivicoli presenti nella regione, ed effettua un confronto con quelli tradizionali. Lo studio mette in evidenza la debolezza economica di molte imprese olivicole. Solo un processo di valorizzazione delle produzioni, infatti, garantisce un maggior valore aggiunto
ASSIGNMENT OF , , and CONFORMERS IN THE ROTATIONAL SPECTRUM OF -PROPANOL
No full textAuthor Institution: Institute of Physics, Polish Academy of Sciences, Al. Lotnikow; 32/46, 02-668 Warszawa, Poland; Department of Physics, The Ohio State University, Columbus,; OH 43210Recent broadband measurements of the rotational spectrum of -propanol up to 375 GHz resulted in determination of precise spectroscopic constants for the conformer of this molecule.}, 428 (2006)} This is most likely the most stable conformer, although four other conformers are predicted to be very similar in energy. Assignment of some of these in cm-wave rotational spectra has previously been reported, but it was not possible to extend that work directly to mm-wave spectra. \vspace{0.2cm} Application of graphical Loomis-Wood techniques built into AABS}, 231 (2005)} and CAAARS}, 229 (2005)} spectral analysis packages eventually allowed successful assignment of the remaining four conformers: , , , and -propanol. It was realised that rotational energies in (, ) and (, ) pairs of conformers are highly coupled, but also amenable to description in terms of the Coriolis interaction mechanism. This allowed very precise determination of some energy level differences, such as cm. The assignment was checked against calculations, and is supported by new, precise determinations of dipole moments of some conformers, which were carried out using supersonic expansion cavity-FTMW spectroscopy
The long-wavelength view of GG Tau A: rocks in the ring world
No full textWe present the first detection of GG Tau A at centimetre wavelengths, made with the Arcminute Microkelvin Imager Large Array at a frequency of 16 GHz (λ = 1.8 cm). The source is detected at >6 σrms with an integrated flux density of S16GHz = 249 ± 45 µJy. We use these new centimetre-wave data, in conjunction with additional measurements compiled from the literature, to investigate the long-wavelength tail of the dust emission from this unusual protoplanetary system. We use an MCMC-based method to determine maximum likelihood parameters for a simple parametric spectral model and consider the opacity and mass of the dust contributing to the microwave emission. We derive a dust mass of Md ~ 0.1 Msun, constrain the dimensions of the emitting region and find that the opacity index at λ > 7 mm is less than unity, implying a contribution to the dust population from grains exceeding ~4 cm in size. We suggest that this indicates coagulation within the GG Tau A system has proceeded to the point where dust grains have grown to the size of small rocks with dimensions of a few centimetres. Considering the relatively young age of the GG Tau association in combination with the low derived disc mass, we suggest that this system may provide a useful test case for rapid core accretion planet formation models
Triangular Constellations in Flows
No full textParticles advected on the surface of a fluid can exhibit fractal clustering. The local structure of a fractal set is described by its dimension , which is the exponent of a power-law relating the mass in a ball to its radius : . It is desirable to characterise the {\em shapes} of constellations of points sampling a fractal measure, as well as their masses. The simplest example is the distribution of shapes of triangles formed by triplets of points, which we investigate for fractals generated by chaotic dynamical systems. The most significant parameter describing the triangle shape is the ratio of its area to the radius of gyration squared. We show that the probability density of has a phase transition: is independent of and approximately uniform below a critical flow compressibility , which we estimate. For the distribution appears to be described by two power laws: when , and when
Dynamic of large particles embedded in shear flows
No full textLarge particles () immersed in a closed turbulent flow tend to explore in a non-uniformly way the cavity in which they are placed. Here we study the slow dynamics of large particles (with various size) advected in closed turbulent flows at different Reynolds numbers. We investigate the spatial sampling experienced by large particles in two fully turbulent closed flows generated between counter-rotating disks (so called von Karman flow), focusing in the slow frequency's (, where is the rotation rate of the driving impellers) and characterize the power spectrum of the slow fluctuations of particles position. Both considered flows share a common feature : the presence of a shear region dividing two mean re-circulation regions ; however the spatial symmetries and the temporal behaviors of both setups are very different. The principal result in this research is that despite these differences both flows exhibit a well defined slow dynamical behavior that can be identified in Fourier space. We report on the universal characteristics of such slow motion
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