112,245 research outputs found
Presenza di collegia professionali nell’Italia adriatica centro-meridionale (regiones II, IV, V, VI e VIII): un’indagine distributiva in base alla documentazione epigrafica latina.
No full textAnalisi della documentazione epigrafica in lingua latina relativa alla presenza di collegia produttivi nei territori costieri dell'Adriatico occidentale (esclusa la regio X)
Novel methods of synthesis of a-Si(H)/Mo multilayers for Extreme UV applications
No full textThis report is focused on the control of the plasma sputtering process used for the synthesis of multilayer mirrors for extreme UV and soft X-ray optical devices. The case of a- Si/Mo and of a-Si(H)/Mo multilayers will be discussed, with emphasis on the study of the basic parameters that control the growth of the single Mo and a-Si(H) layers. The deposition apparatus will be described. The effects of the plasma composition and of the bombardment of the growing layers by Ar+ ions and electrons on the properties of the layers are reported. The hydrogen concentration can be varied up to about 30 at% in the a-Si(H) layers: the hydrogen incorporation leads to a decrease of the material density. The accurate control of the plasma density and of the electron temperature and plasma potential is accomplished through the Langmuir probe method, that permits the accurate measurement of the energy of the Ar+ ions and of their fluence. The possibility of using the present apparatus for the synthesis of a class of ML designed for smaller wavelength applications (down to the water window spectral region) is discussed
Généralités / Generalità
No full textTassaux Francis, Vedaldi Iasbez Vanna, Rigato D., Cicala V. Généralités / Generalità. In: Mélanges de l'École française de Rome. Antiquité, tome 109, n°1. 1997. pp. 268-296
A new study of the 10B(p,)7Be reaction from 0.35 to 1.8 MeV
No full textThe quantification of isotopes content in materials is extremely important in many research and industrial fields. Accurate determination of boron concentration is very critical in semiconductor, superconductor and steel industry, in environmental and medical applications as well as in nuclear and astrophysics research. The detection of B isotopes and of their ratio in synthetic and natural materials may be accomplished by gamma spectroscopy using the 10B(p,)7Be and 11B(p,)12C reactions at low proton energy. Here, the 10B(p,)7Be cross section is reported in the center of mass energy range 0.35 to 1.8 MeV. The keV rays were detected at and using a NaI(Tl) and an HPGe detectors, respectively. In the presented energy range, previous cross section data revealed discrepancies and normalisation issues. Existing data are compared to the new absolute measurement and discussed. The present data have been subtracted from a previous measurement of the total cross section to derive the contribution of the channel
Généralités / Generalità
No full textTassaux Francis, Vedaldi Iasbez Vanna, Rigato D., Cicala V. Généralités / Generalità. In: Mélanges de l'École française de Rome. Antiquité, tome 109, n°1. 1997. pp. 268-296
Polyrhachis omissa Rigato, 2016, n. sp.
No full text<i>Polyrhachis omissa</i> n. sp. <p>(Figures 11 a–c)</p> <p> <b>Diagnosis.</b> A stout species in the <i>viscosa</i> -group, with strongly reduced pilosity, opaque integument, propodeal dorsum and declivity separated by a medially protruding transverse ridge, and petiole armed with a lateral pair of spines and a dorsal pair of teeth. Very similar to <i>P. v i s c o s a</i>, but with ordinary shaped scape and first funicular joint.</p> <p> <i>Holotype worker</i>. HL 1.62, HW 1.49, CI 92, SL 1.80, SI 121, FW 0.41, FI 28 PW 1.33, WL 2.10, HTL 1.70.</p> <p>Clypeus ecarinate, its anterior margin evenly convex and medially crenulate. Head widely oval, distinctly wider around the level of the eyes and much narrower at the level of mandibular insertions. Frons relatively narrow, frontal carinae sinuous. Antennae moderately long. Eyes large and flat, placed close to the posterior corners of the head. Mesosoma stout, nearly flat in profile, mesonotum more than twice as wide as long. Promesonotal suture narrow, but well marked, metanotal suture faint, hardly visible. Pronotal teeth well developed and slightly diverging. Propodeal dorsum bearing an upturned small tooth at each posterior corner; propodeal dorsum and declivity separated by a thin ridge strongly medially raised as an antero-posteriorly flattened lobe. Petiolar scale wide, armed with 4 equidistant spines and teeth: a lateral pair of spines and a dorsal pair of sharp teeth; the space between dorsal teeth straight. First gastral tergite anteriorly concave.</p> <p>Integument matt; ground sculpture finely reticulate-punctate all over the body and more superficially so on appendages. A superimposed, irregular reticulate rugulosity covers most of head and mesosoma in a somewhat areolate pattern.</p> <p>Standing hairs almost lacking: occurring only at the anterior clypeal margin and on gastral tergites III–V and all sternites. Pubescence very short and sparse, hardly visible on the body.</p> <p>Colour black throughout.</p> <p> <i>Paratype gynes</i> (n=12). HL 1.76–1.99, HW 1.49–1.72, CI 82–88, SL 1.81–2.13, SI 116–128, FW 0.42–0.50, FI 28–30, ScW 1.73–2.05, MnL 2.13–2.63, WL 2.93–3.50, HTL 1.85–2.21, Anterior wing length 8.1-9.3.</p> <p>With the usual caste differences from the worker and with weakly convex eyes. Wings moderately infuscated.</p> <p> <i>Paratype male</i>. HL 1.24, HW 1.10, CI 89, SL 1.40, SI 127, ScW 1.53, MnL 2.16, WL 2.87, HTL 1.95. (I confidently assign to this taxon a single male collected together with several gynes in Yemen).</p> <p>Mandibles narrow, almost unarmed, with a short masticatory margin bearing a blunt apical cleft tooth and 1 or 2 minute blunt denticles. Anterior clypeal margin entire, evenly convex. Head round with relatively small eyes (maximum eye length: 0.47), Ocelli well developed: MOD (mid-ocellus diameter): 0.18; distance between mid ocellus and each lateral one <MOD. Distance between lateral ocelli: 0.46. Length of anterior wing: approx. 7.4. Petiolar scale thick, wide and low; in frontal view the petiolar dorsum is evenly weakly convex and is separated from sides by a weak blunt angle.</p> <p>Integument subopaque, finely reticulate-punctate; only the head dorsum bears a trace of rugulo-reticulation recalling that of female castes.</p> <p>Pilosity reduced, mostly as in female castes.</p> <p>Body and antennae blackish; legs dark brown, mandibles and most articulations slightly paler. Wings as in gyne.</p> <p> <i>Paratype workers</i> (n=10). HL 1.56–1.80, HW 1.39–1.64, CI 88–92, SL 1.68–2.00, SI 118–127, FW 0.35–0.44, FI 25–28, PW 1.20–1.56, WL 1.90–2.32, HTL 1.56–1.98. Mostly consistent with the holotype, but with some minute variations. Eyes more or less slightly convex, metanotal suture sometimes completely lacking dorsally, and median lobe of propodeum reduced to a low convexity.</p> <p> Holotype worker. <b>SOMALIA</b>: Balad, 28.ix.1986 (<i>L. Bartolozzi</i>) (MSNM).</p> <p> Paratypes. <b>YEMEN</b>: Sokna (Tihama), m 200, 20.viii.1965 (<i>G. Scortecci</i>) (17 g, 1 m, MSNM). <b>ETHIOPIA</b>: “da Dimé al Bass Narok”, viii–ix.1896 (<i>Bottego</i>) (1 g, MSNG) [misidentified by Emery (1899) as <i>P. viscosa</i>]; Banno, Sagan-Omo, 10.v.1939 (<i>E. Zavattari</i>) (1 w, MSNG); Caschei, Sagan-Omo, 6.vii.1939 (<i>E. Zavattari</i>) (3 g, MSNG). <b>SOMALIA</b>: “M. Umberto I”, iii.1892–93 [?] (<i>E. Ruspoli</i>) (1 g, MSNG); Ganana, iii.1892–93 [?] (<i>E. Ruspoli</i>) (2 g, MSNG); “Boran Galla, Medio Ganale”, vi.1893 (<i>V.</i> Bottego) (1 w, MSNG); “Basso Ganana”, vii– viii.1893 (<i>V.</i> Bottego) (3 w, MSNG); Eil (Nogal), iii–iv.1938 (<i>S. Venzo</i>) (2 g, MSNM); Eil (<i>A. Falzoni</i>) (1 g, MSNM); Gardo, 810m, 21.x.1957 (<i>G. Scortecci</i>) (2 g, MSNM); same data, but 22.x.1957 (2 g, MSNM); Afgoi, v.1972 (<i>L. Masutti</i>) (2 g, MSNM); Afgoi, 2.x.1986 (<i>L. Bartolozzi</i>) (1 w, MSNM). <b>KENYA</b>: Mackinnon (30 km ca. N-NW of Mombasa), ix.1946 (<i>Meneghetti</i>) (1 w, 1 g, MSNM); Malindi, xii.1993 (<i>R. Regalin</i>) (3 w, MSNM); Archer’s Post, Uaso Nyiro river, 2300’, 6.xii.1969 (<i>M.E. Irwin & E.S. Ross</i>) (4 g, CAS).</p> <p> <b>Comment.</b> I often found specimens of <i>P. o m i s s a</i> labelled as <i>P. v i s c o s a</i> and mixed with it, but <i>omissa</i> always lacks the distinctive antennal features that separate <i>viscosa</i> from all other African <i>Polyrhachis</i> known so far. <i>Polyrhachis viscosa</i> has a strongly widened apex of the scape and a strongly depressed first funicular joint (see Fig. 22 in Bolton, 1973). This feature is unique to <i>viscosa</i> and seemingly constant. Although I found several gynes assignable to <i>P. omissa</i> collected in Yemen, Collingwood and Agosti (1996) in their survey of Arabian ants mentioned <i>P. v i s c o s a</i> and <i>P. lacteipennis</i> F. Smith only. <i>Polyrhachis lacteipennis</i> superficially recalls <i>viscosa</i> and <i>omissa</i>, but belongs to the non-African subgenus <i>Myrmhopla</i> and has a slender and immarginate mesosoma and other very distinctive features.</p> <p> I also examined the types of <i>P. an t i n or i i</i> Emery, which Bolton (l.c.) did not see and synonymised with <i>P. viscosa</i>. I can confirm that <i>antinorii</i> is conspecific with <i>viscosa</i>; therefore no old available names are assignable to <i>omissa</i>.</p> <p> The main features separating <i>omissa</i> from <i>viscosa</i> workers can be summarized as follows:</p> <p> In addition, most <i>omissa</i> specimens have a few standing setae on the second gastral tergite, while all of the approximetely 20 <i>viscosa</i> specimens I examined have no erect hairs on the second gastral tergite; but this difference might be due to population differences, age or degree of abrasion of specimens.</p> <p> Among the <i>viscosa</i> -group species listed by Bolton only <i>viscosa</i> itself and <i>nigrita</i> share the same arrangement of petiolar spines as in <i>omissa</i>: a long lateral pair, and a much shorter, often tooth-like, dorsal pair. Moreover, <i>nigrita</i> differs from <i>viscosa</i> and <i>omissa</i> especially by its longer propodeal teeth and by the propodeal dorsum evenly rounding into the declivity.</p>Published as part of <i>Rigato, Fabrizio, 2016, The ant genus Polyrhachis F. Smith in sub-Saharan Africa, with descriptions of ten new species. (Hymenoptera: Formicidae) in Zootaxa 4088 (1)</i> on pages 34-36, DOI: 10.11646/zootaxa.4088.1.1, <a href="http://zenodo.org/record/261854">http://zenodo.org/record/261854</a>
VUV Reflectance measurements and optical constants of SiC thin films
No full textOptical constants of SiC thin films deposited with RF magnetron sputtering have been derived in the VUV. The films have been deposited
with different parameters resulting in various C/Si ratios. Reflectance measurements have been made with a dedicated facility in the range
300–1300 ́°A . Index of refraction and absorption coefficient have been derived by fitting the reflectance data with the calculated ones
Polyrhachis submarginata Rigato, 2016, n. sp.
No full text<i>Polyrhachis submarginata</i> n. sp. <p>(Figures 12 a–c)</p> <p> <b>Diagnosis.</b> A relatively large species in the <i>revoili</i> -group, with somewhat slender head and appendages, incomplete and weak pronotal margination, and very weak propodeal ridges.</p> <p> <i>Holotype worker</i>. HL 1.66, HW 1.25, CI 75, SL 2.02, SI 162, FW 0.45, FI 36, PW 1.13, WL 2.17, HTL 1.98.</p> <p>Clypeus medially subcarinate and with anterior margin bearing a protruding rectangular lobe, whose lateral corners are right angled. Head in full face view moderately elongate, oval, wider behind than in front, posterior margin widely convex. Eyes moderately large and convex. Mesosoma stout and evenly convex in profile. In dorsal view pro- and mesonotum distinctly transverse; propodeal dorsum somewhat longer than wide. Pronotum laterally weakly marginate and armed with two small diverging teeth; the margination incomplete and somewhat difficult to see even because of sculpturation and pubescence. Mesonotum and propodeum immarginate. Propodeal dorsum with two faint posterolateral ridges at its posterior corners, medially propodeal dorsum and declivity confluent in a blunt curvature. Promesonotal suture slightly impressed, metanotal suture faint. Petiole with a dorsal pair of widely separated, moderately long and diverging spines and a pair of lateral sharp teeth; the space between dorsal spines straight. First gastral tergite anteriorly weakly concave.</p> <p>Mandibles faintly longitudinally striolate and with sparse piligerous pits, mostly shining. The whole body and appendages finely reticulate-punctate. Body opaque, appendages weakly shining. Head and mesosomal dorsum with a superimposed, fine, irregular longitudinal rugulation.</p> <p>Standing hairs abundant everywhere and longer on head and mesosoma. Hairs on scapes at most a little longer than scape diameter at midlength; hairs on tibiae at most about as long as half the maximum tibial width. Body and appendages coated with dense, short and silvery to slightly golden pubescence, not masking the sculpturation and longer on mesosoma and petiole.</p> <p>Colour black, most of the funicular joints and mandibular apices ferrugineous.</p> <p> <i>Paratype worker</i>. HL 1.62, HW 1.22, CI 75, SL 1.98, SI 162, FW 0.47, FI 39, PW 1.19, WL 2.3, HTL 1.98. All main features as in the holotype.</p> <p> Holotype. <b>CENTRAL AFRICAN REPUBLIC</b>: Res. Dzanga–Sangha, 12.7 km, 326° NW Bayanga, 3°00.27’ N 16°11.55’ E, 420 m, 10–11.v.2001 (<i>S. van Noort</i>) (CAS: CASENT0087089 CAR01-M78).</p> <p> Paratype. <b>CENTRAL AFRICAN REPUBLIC</b>: same data as the holotype, except 14–15.v.2001 (<i>S. van Noort</i>) (1 w, CAS: CASENT0088752 CAR01-M123).</p> <p> <b>Comment.</b> <i>Polyrhachis submarginata</i> is characterised by weak pronotal margination and propodeal ridges, and a relatively high SI. <i>Polyrhachis submarginata</i> is similar to <i>P. otleti</i> and the main differences between them are reported in the key. <i>Polyrhachis submarginata</i> seems to link <i>revoili</i> -group species with immarginate mesosoma and with well defined, although incomplete, margination. <i>Polyrhachis volkarti</i> Forel is similar but is smaller, has a usually immarginate pronotum, distinctly more slender mesosoma. well developed propodeal ridges, and a higher SI.</p> <p> <i>Polyrhachis kohli</i>, <i>P. submarginata</i> and <i>P. volkarti</i> look very similar, and share some important features: 1) a shallow clypeal lobe; 2) relatively long scapes, SI> 150; 3) abundant pilosity on body and appendages; 4) mesosoma completely immarginate or almost so; 5) propodeal dorsum and declivity separated by a pair of small, more or less developed, ridges; 6) petiole armed with a pair of moderately long median spines and a pair of lateral much shorter teeth; 7) rough, mostly irregularly longitudinal rugulose sculpturation on head and mesosoma; 8) Body coated with abundant, relatively short and moderately dense greyish pubescence never hiding the sculpturation.</p> <p>The main differences can be summarized as follows:</p> <p> <b>Diagnosis.</b> The largest species of the <i>revoili</i> -group known so far, with almost complete lateral marginations of the mesosoma and a continuous well developed ridge separating propodeal dorsum from declivity.</p> <p> <i>Holotype worker</i>. HL 2.60, HW 2.37, CI 91, SL 2.50, SI 105, FW 0.80, FI 34, PW 2.05, WL 3.5, HTL 2.77.</p> <p>Clypeus subcarinate, with anterior margin arcuate and medially bearing a faint shallow rounded lobe. Head trapezoidal, wider behind than in front, posterior margin and sides widely convex. Eyes moderately large and convex, close to the posterior corners. Mesosoma in profile evenly weakly convex, mesonotum almost flat. Promesonotal suture well-developed, metanotal suture weak and hardly interrupting the dorsal sculpturation. Pronotum with a pair of strong teeth at its anterior corners and laterally clearly marginate, the margination interrupted just before the promesonotal suture. Mesonotum with a weaker margination, interrupted before the metanotal suture. Lateral margination of propodeal dorsum faint, detectable along about its anterior half. Propodeal dorsum and declivity well-separated by a continuous ridge which is slightly higher medially. Petiole with a dorsal pair of distant, moderately long and diverging spines and a pair of lateral shorter ones; the space between the dorsal spines straight. First gastral tergite anteriorly weakly concave.</p> <p>Mandibles distinctly longitudinally striolate and with sparse piligerous pits. Clypeus superficially finely reticulate-punctate. Head dorsum prevailingly longitudinally costulate with a faint ground sculpture; head sides and cheeks (malar space) mostly reticulate-rugose with finely reticulate-punctate ground sculpture. Mesosomal dorsum finely longitudinally rugulose with reticulate-punctate ground sculpture. Mesosomal sides mostly finely longitudinally rugulose; mesopleuron less evidently so. Petiole finely reticulate-punctate with superimposed rugulation. Gaster finely reticulate-punctate throughout.</p> <p>Short to moderately long standing hairs abundant on all body surfaces and appendages. On the legs hairs are shorter than the maximum tibial width. Hairs on scapes are at most slightly longer than scape diameter at midlength. Body and appendages coated with dense, short and greyish pubescence, not masking the sculpturation and sparser on head dorsum and clypeus.</p> <p>Colour black, except a brown dorsal strip on femurs and tibiae and pale ferrugineous gastral apex.</p> <p> Holotype. <b>TANZANIA</b>: Morogoro, Kilombero, Zoosite 2, 11.3 km ESE Mbingu, 8.20483 S 36.36055 E, 277 m, 23.x.2007, closed miombo woodland, pitfall trap, FRO 2007_2_P (<i>E. Jew & L. Williams</i>) (SAM: CASENT0250168).</p> <p> <b>Comment.</b> <i>Polyrhachis terminata</i> is unique for its large size and the complete ridge running between propodeal dorsum and declivity. This ridge is much stronger than the incomplete and weak margination of the propodeal sides.</p>Published as part of <i>Rigato, Fabrizio, 2016, The ant genus Polyrhachis F. Smith in sub-Saharan Africa, with descriptions of ten new species. (Hymenoptera: Formicidae) in Zootaxa 4088 (1)</i> on pages 39-41, DOI: 10.11646/zootaxa.4088.1.1, <a href="http://zenodo.org/record/261854">http://zenodo.org/record/261854</a>
Structural characterization of lead zirconate titanate thin films prepared on different electrodes and on silicon substrates
No full textLead zirconate titanate (PZT) thin films were deposited by rf magnetron sputtering on Pt/Ti/SiO(2)//Si, Au/Ti/SiO2//Si, ITO//glass electrodes and on Si (100) substrates. As deposited films show large excesses of Pb and O and contain different Pb oxides. Annealing treatments in air at 650 and 750 degrees C carried out in a preheated muffle furnace lead to a decrease of Pb and O content and to formation of the perovskite phase via an intermediate nanocrystalline pyrochlore phase. Phase pure perovskite films are obtained on Pt and ITO electrodes by annealing at 750 degrees C for similar to 10 min, while for the same treatment significant amounts of pyrochlore remained on Au electrodes and on Si substrates
Optical and structural properties of low thickness lead zirconate titanate films on sapphire substrates prepared via sol-gel method
No full textLead zirconate titanate (PZT) thin films in the range of 35-90 nm were deposited on a sapphire (1000) substrate using the sol-gel preparation method by diluting a PZT solution at different levels and using dichloromethane as the solvent. The microstructure, surface morphology, and stoichiometry of the films were studied by x-ray diffraction, atomic force microscopy, and Rutherford backscattering. Very smooth films characterized by single perovskite and mixed pyrochlore/perovskite polycrystalline phases were obtained and their optical properties were studied by spectroscopic ellipsometry in the ultraviolet-visible-near-infrared region. The refractive index was evaluated by analyzing the spectroscopic ellipsometry spectra. The ellipsometric data were also used to evaluate the bandgap energy of the films. The results show that the optical parameters of the films depend on the crystalline structure and demonstrate that higher bandgaps are obtained for perovskite films as compared to pyrochlore or mixed pyrochlore/perovskite structures. Data also confirm the higher bandgap of the amorphous structure compared to the polycrystalline PZT phases
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