1,721,104 research outputs found
Geografia e scuola in Italia, (in collab. con P. Persi), in "Studi Urbinati", anno LXIX, 1997, pp. 149- 159
No full textL’ENIGMA LIBANESE. TRA GEOPOLITICA E PERCEZIONE LETTERARIA
No full textTerritorio di congiunzione tra Anatolia e Mar Rosso, area di contatto tra Mesopotamia e Mediterraneo, rivela nei secoli la sua centralità di ganglio di incontri-scontri tra poteri egemoni e sfere culturali collidenti. Di qui il suo destino di spazio conteso e terra martire, per le genti che si sono ostinate a restarvi, e spazio di fuga, per quanti, con profondo rimpianto, hanno deciso di abbandonarlo per paesi vicini, come l’Egitto, oppure lontani come gli Stati Uniti, il Brasile o l’Australia.
La letteratura libanese contemporanea consente di seguirne le evoluzioni recenti e di cogliere spunti preziosi per la ricerca di soluzioni, temerarie forse ma non impossibili, seppure nei contesti tormentati e discordi del Vicino Oriente
Insediamenti mononucleari di sommità e approvvigionamento idrico. Casi di studio nel Montefeltro tra Quattro e Cinquecento
No full text
Beni culturali territoriali tra identità e recupero. Riflessioni ed esperienze in ambito marchigiano. Territorial cultural heritage between identity and recovery. Discussion and experiences in the Marche region.
No full textI beni culturali territoriali (materiali e immateriali) possiedono implicazioni regionali di tutto rilievo come espressione d’identità individuale e collettiva che, in diverso modo, tendono a conservare nel tempo. Con i mobili contesti storico-economici, mutano i loro ruoli funzionali e semantici, ma non i valori rappresentati che continuano ad agire sul territorio, sul suo assetto, sulla sua immagine e produttività. Il bene territoriale è portatore polisemico e ogni intervento di recupero e ricerca di funzioni compatibili deve coniugare ambiente, cultura, arte e architettura, storia sociale ed economica, tutela e sviluppo. Ne deriva una riflessione su metodologia e fasi di lavoro finalizzato, oltre che alla salvaguardia e nuova fruizione del bene comune, anche per scoprire e riannodare le sottili ed esili trame territoriali. La scheda predisposta per la ricerca sulle residenze signorili nelle campagne marchigiane evidenzia la composita e complessa problematicità della questione che andrebbe affrontata anche nella più ampia prospettiva di rivalorizzazione delle aree interne
Near-infrared images of galactic masers I. Association between infrared sources and masers
No full textWe present the first results of an extensive near infrared survey of galactic H_2_O and OH masers in high-luminosity star forming regions (SFR) aimed to see if there are near-infrared (NIR) sources directly associated with the masers. Seventeen fields for which accurate VLA positions of the masers were available have been imaged in the three J, H, and K NIR broad band filters with pixel resolution of 1.34 arcsec/pixel and a field of view of roughly 3'x3'. All observed fields show a high density of K-band sources, completely undetected in previous surveys, probably stellar clusters located in the SFR. From numerical simulations we find that the distributions of the observed first-neighbour K-band source to the maser is very unlikely due to chance coincidence with uniformly distributed field sources. For this reason, the infrared source nearest to the maser (<~10 arcseconds) is considered to be associated with the maser. All these sources have distinctive characteristics: they are weak and detected only in K, or if the H magnitude is measurable, they show an H-K colour index greater than 2. Although not in all sources there are high sensitivity-high resolution radio continuum observations, only few of the K-band/maser sources are closely associated with known ultracompact (UC) HII regions. After considering several plausible alternatives we find that the observed NIR emission is produced by a young stellar object (YSO) surrounded by a dusty circumstellar envelope. In the evolutionary scheme of SFR this result places the NIR/maser sources in a stage preceding that of UCHII regions, in which the radio continuum from ionized gas is undetectable with present sensitivities either because so much reduced by self-absorption or by dust absorption of stellar UV photons in the very dense envelope of the YSO or intrinsically weak due to low UV photon fluxes
Sub-arcsec resolution infrared images of the star forming region G 35.20-1.74
No full textWe present J(1.25μm), H(1.65μm), K(2.2μm), H_2_(2.125μm) and 11.2μm infrared images at sub-arcsec resolution of an area centered around the star forming region G 35.20-1.74. In J, H and K a cluster of early type stellar sources with infrared excess clearly stands out with respect to the background distribution and is associated with a diffuse K emission around an UC HII region (which is the brightest source at K). No H_2_ emission is detected in narrow-band images at 2.125μm. At 11.2μm six components are detected. The brightest one (MIR3) is extended and coincides with the UC HII region. The source with steepest IR spectrum and the largest infrared excess (MIR1) is associated with an H_2_O maser and a near IR source detected only at K. It is separated from the IR cluster and at a distance of 20'' from the UC HII region. The IR emission comes from a local young stellar object (YSO) associated with the maser. The lack of radio continuum emission from MIR1 confirms that H_2_O masers can trace the youngest evolutionary stages of massive YSOs, much before the appearance of a radio UC HII region and shows that star formation is not limited to the IR cluster (where most probably it has already come to an end) but is still taking place in other parts of the molecular cloud. Of the other 11.2μm sources, three (MIR2, MIR4 and MIR5) present IR excesses and are similar to MIR1, while MIR6 appears to be a reddened early-type star. The morphology of the entire star forming complex, taking into account also molecular and sub-mm observations, is indicative of different and independent episodes of star formation taking place in the same molecular cloud
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