1,397 research outputs found
Transition Between Open and Closed Wake in 3D Linear Aerospike Nozzles
No full textLinear aerospike nozzles are envisaged as a possible device able to improve launcher engine performance. One of the most interesting properties of these nozzles is the possibility of a good integration with the vehicle. Tb improve the knowledge of the flow-field and performance of aerospike nozzles, they are studied numerically, with particular attention to the differences between the basic two-dimensional nozzle, usually considered in the design phase, and the more realistic three-dimensional nozzle. The study considers different plug lengths and ambient pressures to assess the role of the linear plug side truncation on the base pressure behavior. Numerical tests are carried out at supersonic flight Mach number. Copyright © 2005 by M. Geron and R. Paciorri.F. Nasuti, F. Sabetta, E. Martelli
Isotopes of noble gases from fluid inclusions in mafic phenocrysts from extrusives and ultramafic xenoliths of Stromboli (Aeolian Islands, Italy)
No full textWe present a study of noble gases abundances (He, Ne, Ar) and isotopic ratios (He, Ar) in olivine- and clinopyroxene-hosted fluid inclusions from basaltic Low Porphyritic (LP) pumices and High Porphyritic (HP) scorias, respectively of paroxysms and mild explosions of the Stromboli present activity [1] and from ultramafic xenoliths of the 2 ka ago San Bartolo lavas [2]. New petrologic studies on such ultramafic xenoliths show that they are mostly wherlites (subordinately lherzolites), with slightly protogranular to porphyroclastic texture. Thermo-barometric estimates on the mineralogical assemblage indicate that ultramafic xenoliths equilibrated at depth well below the crust-mantle transition of Stromboli.
While Ar isotopes are dominated by a clear atmospheric signature in all the samples, 3He/4He from LP pumices and S. Bartolo ultramafic xenoliths converge to a value of 4.2-4.7 Ra, with relatively high gas content. Conversely, the low gas content of the HP scorias allowed us to measure chemical concentrations but not their 3He/4He ratio. Inferences found out from gas content are therefore in full agreement with previous knowledge about differences in volatile content between HP and LP magmas. The 3He/4He measured values are much lower than those of most primitive mantle terms of the Sicilian volcanism (7 ± 0.6 Ra [3]), due to contamination at mantle level beneath Stromboli, operated by the Ionian subducting slab.
On the basis of the measured 3He/4He in the LP pumices and ultramafic xenoliths, helium in thermal waters from the Stromboli basal aquifer is a mixing of a mantle-derived and an atmospheric term. The 3He/4He values measured in the rocks constitute the upper limit that should be expected in thermal fluids in case of effusions and/or paroxysms.
References. [1] Bertagnini, A., Metrich, N., Landi, P., Rosi., M. (2003): J. Geophys. Res., 108, 1-15; [2] Laiolo, M. & Cigolini, C. (2006): Bull. Volc., 68, 653-670; [3] Martelli, M., Nuccio, P.M.., Stuart, F., Di Liberto, V., Ellam, R.M. (2008): Geochem. Geophys. Geosyst., 9, doi:10.1029/2007GC001730
A Florentine family in crisis: the Strozzi in the fifteenth century.
No full textPhDIn 1434 the Strozzi lineage had held a leading position in
Florentine society and government for at least one hundred and fifty
years, and was one of the largest and wealthiest of the city's
patrician lineages. The records of the catasto of 1427 and of the
scrutiny of 1433 are used to give a profile of the dominant social,
economic and political position of the Strozzi before the advent of
Medicean dominance. Their record of electoral success, and the
political and cultural leadership of influential and respected men
such as Palla di Nofri and Matteo di Simone, with other factors, put
the Strozzi amongst the greatest enemies of the victorious Medicean
regime of late 1434. The effects of political opposition and exile
on the lineage are examined both directly, through records of office-holding,
and indirectly through such indicators as marriage alliances
and household wealth. The two most prominent lines of the Strozzi
were exiled after 1434. Palla di Nofri's life and preoccupations in
his Paduan exile are examined, together with the lives of his sons;
none of these Strozzi ever returned to Florence, pursued as they were
by the enmity of the Medicean regime. The very different careers of
Filippo di Matteo and his brother Lorenzo are also examined: how they
succeeded in founding a lucrative bank in Naples, and in returning to
Florence to 'rebuild' (rifare) the position of the Strozzi lineage
there. The final decades of the century saw the Strozzi in an
economically more secure position, due substantially to the efforts
of Filippo. Except for a very small number of its members admitted
into the regime, most of the lineage is here shown to have remained
excluded from significant political office until after the fall of
the Medici regime in 1494
Studio della Fluidodinamica Interna di Ugelli Propulsivi di Tipo Dual Bell
No full textFilippo Sabetta, Maurizio Di Giacinto, Franco Rispol
MARIO MARTELLI, Zapping di varia letteratura
No full textL'amplissimo volume del Martelli, che raccoglie materiali filologici, critici ed estetici accumulati in un decennio di lavoro, da annotazioni semplici a microsaggi, intorno ad autori italiani di ogni secolo ha una struttura aperta, che incoraggia il lettore a un libero esercizio di connessioni tematiche, così da dare coesione alle 256 schede passando dall'una all'altra. Una esemplificazione di lettura può privilegiare sezioni quali la VII, sul valore espressivo del brutto in autori dal Tre all'Ottocento, sul LVI, dedicata a profili di personaggi tragici femminili, la CXLV, intorno a Montale Da una scheda come la CXV, L'attacco per congiunzione, sviluppata con citazioni di Foscolo, Petrarca, Poliziano, Stecchetti, il Martelli muove per un excursus sulla e congiunzione narrativa del giornalismo moderno. Si può segnalare autonomamente, in proposito, l'uso ormai corrente della e commerciale, &, in sostituzione della grafia abituale; e si può motivare tale ricorso scomposto al segno della associazione mercantile, per indicare un rapporto congiuntivo comune, con la sovreccitazione e l'effettismo della prosa giornalistica nell'età dell'economia egemone. Seguono altre autonome considerazioni sulla competenza di ordine generale, in fatto di storia della letteratura italiana, propria di studiosi di una generazione ormai lontana dal tempo presente. Oggi la passività e la dispersività dell'attività intellettuale, in cui hanno particolare responsabilità –anche secondo l'opinione di psicologi ed esperti di processi cognitivi- i mass media (l'automatismo dello zapping televisivo, al quale va opposta la libera ricerca dello studioso di letteratura), rendono quasi impossibile una visione stereoscopica, globale, di una forma di civiltà come la letteratura italiana nel suo sviluppo storico
A diffuse glioma with oligodendroglial‐like cells and extensive calcifications
No full text: The tumor showed extensive microcalcifications and cells with oval, nuclei and a clear perinuclear halo (A), positive immunostaining for OLIG-2 (B), GFAP (C), and CD34 (D), and intermingled Neu-N-positive neurons (E). FISH revealed multiple signals for the centromere of chromosome 7 (gains) (green probe) and the EGFR locus (red probe) (F, left), and a single signal for the centromere of chromosome 10 (loss) (F, right)
Inclusione del metossibutropato in ß- ed idrossipropil ß-ciclodestrine: diverse metodiche di preparazione a confronto
No full textNon disponibil
Drug release from compressed Eudragit RS 30D coated beads
No full textTablets of different hardnesses and compositions were prepared with an original theophylline granulate previously coated with Eudragit RS 30D. Dissolution studies of each tablet formulation were performed to verify any kinetic variationfrom the dissolution profile. This was obtained by filling with the same coated granules in a hard gelatine capsule. While the dissolution profiles of the capsules possesses very good linearity, the tablet kinetics gradually deviate from this linearity with an increase in the percentage of the coated granules in the formulation. Tablet hardness has only a marginal influence on this kinetic deviation
New Controlled-Release Ibuprofen Tablets
No full textTablets containing two different doses of ibuprofen are realized. The first possesses very fast release kinetics, while the second has slow and linear release kinetics. This allows drug to produce a therapeutic effect quickly and to maintain it for a long time with only one administration unit. Such tablets are obtained by compression of a mixture of two very different kinds of granulates: an ibuprofen-starch granulate and an ibuprofen–Eudragit RS microsphere granulate. Specific proportions of mixtures of them give the described result after compression at particular tablet hardnesses
Interactions between Lonidamine and b- or hydroxypropyl -b- cyclodextrin
No full textThe possibility of obtaining inclusion complexes between lonidamine and β- or hydroxypropyl-β-cyclodextrin have been evaluated by phase solubility diagram, differential scanning calorimetry (DSC), and x-ray diffractometry. The applied complexation methods were spray-drying, kneading, and solid dispersion. DSC and x-ray analyses of the powders revealed an external interaction between lonidamine and cyclodextrins. Dissolution profiles of the obtained powders were also studied to define the most appropriate preparation method and molar ratio to use in attempts to increase lonidamine water solubility
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