1,710 research outputs found

    About the use of entanglement in the optical implementation of quantum information processing

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    We review some applications of entanglement to improve quantum measurements and communication, with the main focus on the optical implementation of quantum information processing. The evolution of continuos variable entangled states in active optical fibers is also analyzed.Comment: 8pages, invited contribution to Quant. Interf. IV (ICTP Trieste 2002

    An “Unexpected” Rock Failure in a Limestone Open Pit Mine

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    On 28th October 2004 a rock failure occurred in a limestone open pit quarry in Tuscany (Italy). The phenomenon evolved slowly with the collapse of about 1000 cubic meters. The complex failure mechanism mainly involved plane sliding along stratifications with rotation and block toppling. The phenomenon continued to evolve slowly and on 3rd November failure extended to the neighbouring portion of rock with a total collapse of about 5000 cubic meters of rock. Failure analysis took advantage of an accurate characterization of geology, geometry and mechanical properties of the collapsed rock mass. Such analysis led to the conclusion that the failure has been caused by the concurrence of various factors, namely: - unfavourable dip and dip directions of stratification which daylight in the slope face; - possible reduction of the angle of shear resistance available along stratification especially as a consequence of intense rainfall and vibrations

    3D FEM and DEM Analyses of Underground Openings in Competent Rock Masses

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    The paper is aimed at comparing the results of numerical analyses of underground openings in competent rock masses like the Carrara Marble (Italy) by considering a real and well documented case study. More specifically, 3D FEM and DEM analyses were carried out on a rock-mass model interested by two faults and three sets of discontinuities. The geometrical model is representative of deep underground openings where spalling-cracks and rock bursts can occur. PLAXIS 3D and 3DEC were used for the analyses. Intact rock and rock mass characterization of Carrara Marble was inferred from available technical literature. The analysis results were compared in terms of principal stresses and displacements in a number of monitoring points around the opening. The main practical interest is to find out a reliable approach for evaluating the stability of very large openings in a competent rock mass like Carrara marble. For such a purpose, a number of available in-situ stress measurements were used

    A new monoclinic polymorph of 3-diethyl­amino-4-(4-meth­oxy­phen­yl)-1,1-dioxo-4H-1λ6,2-thia­zete-4-carbonitrile

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    A new monoclinic form of the title compound, C14H17N3O3S, has been found upon slow crystallization from water. Another monoclinic form of the compound was obtained previously from a mixture of dichloro­methane and diethyl ether [Clerici et al. (2002 ▶). Tetra­hedron, 58, 5173–5178]. Both phases crystallize in space group P21/n with one mol­ecule in the asymmetric unit. The formally single exocyclic C—N bond that connects the –NEt2 unit with the thia­zete ring is considerably shorter than the adjacent, formally double, endocyclic C=N bond. This is likely to be due to the extended conjugated system between the electron-donor diethyl­ammine fragment and the electron-withdrawing sulfonyl group. In the newly discovered polymorph, the meth­oxy group is rotated by almost 180° around the phen­yl–OCH3 bond, resulting in a different mol­ecular conformation

    GNSS signal acquisition in the presence of sign transitions

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    The next generation of Global Navigation Satellite Systems (GNSS), such as Galileo [1] and GPS modernization [2], will use signals with equal code and bit periods, which will introduce a potential sign transition in each segment of the signal processed in the acquisition block. If FFT is used to perform the correlations a sign transition occurring within the integration time may cause a splitting of the main peak of the Cross Ambiguity Function (CAF) into two smaller lobes along the Doppler shift axis [3]. In this paper a method to overcome the possible impairments due to the lobe splitting is proposed and validated by simulation

    Il diritto di partecipazione nell’esperienza delle Comunità Autonome Spagnole e le esigenze di proceduralizzazione degli strumenti partecipativi.

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    La forte e ormai sistemica crisi delle democrazie rappresentative contemporanee ha costituito un terreno fertile per la proliferazione di modelli rimediali, sviluppati sotto l’egida della democrazia partecipativa e dell’ideale deliberativo. Nonostante la casistica ricomprenda strumenti di diversa natura, si è lontani dall’affermazione di una disciplina organica della partecipazione. Si propone, dunque, l’analisi della disciplina adottata a livello autonomico in Spagna. In tale contesto, le soluzioni adottate a livello substatale in Spagna esprimono una evidente strategia uniformatrice che ha consentito di individuare e delineare un diritto autonomico di partecipazione cittadina. Tale soluzione si distanzia, come si vedrà, dalla via seguita dalle regioni italiane che hanno regolamentato processi partecipativi fortemente strutturati, pur optando per strumenti diversi.The strong and systemic crisis of representative democracy formed a fertile ground for the proliferation of remedial models, developed under the umbrella of participatory democracy and deliberative ideal. Despite case studies include different solutions, we are far from the affirmation of a uniform regulation of participatory processes. The article proposes a study about the Spanish autonomous discipline of participation. The solutions adopted in this context highlight a standardizing logic that outlines the bases of the autonomous right of civil participation. In a different way, Italian regions have deeply structured the participatory processes, opt for a different and heterogeneous solutions

    Sabellidae (Annelida) from the Faro coastal lake (Messina, Ionian Sea), with the first record of the invasive species Branchiomma bairdi along the Italian coast

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    In the present paper, morphological and ecological observations on 4 sabellid taxa, Branchiomma bairdi, B. luctuosum,Megalomma lanigera and Myxicola sp., collected from the coastal lake of Faro (Messina, Ionian Sea) (26-36 psu), are reported. Megalomma lanigera, Myxicola sp. and B. luctuosum were collected from the soft bottom in shallow water and B. bairdi from the hard bottom of an internal channel. The presence of the latter is remarkable, as there is no previous record of this species along the Italian coast, and it confirms the lake of Faro as a very favourable environment for the introduction of alien species, which has occurred frequently as a result of aquaculture. High intraspecific variation was observed for M. lanigera, whilst more extensive analysis is required to ascertain the taxonomic status of the Myxicola specimens, including a review of all Mediterranean data currently attributed to M. infundibulum

    Monster parastomal pyoderma gangrenosum effectively treted by topical tacrolimus.

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    Terapia del pyoderma gangrenoso parastomale refrattario in malattia di Crohn. Il trattamento si è basato sull'applicazione topica di tacrolimus pomata. Dopo la suddetta terapia si è osservata la guarigione delle lesioni cutanee

    Spatial extent of recent vertical tectonic motions misured in NE Sicily coastal area. Insights from marine geology and coastal geomorphology studies.

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    Vertical position of sea-level, pointed out by related deposits and morphologies, provide useful markers to estimate tectonic uplift rates. For the Holocene very high uplift rates are misured in the northeast Sicily coast (Antonioli et al., 2009). This study compare vertical tectonic movements and marine geology data in the coastal sector between Capo d\u2019Orlando and Brolo (NE Sicily); tectonic lineaments show different trends both onland (Nigro & Sulli, 1995) and offshore (Nicolich et al.,1982) and also the morphological response follow closely this difference. The geomorphologic survey provided data on Holocene uplift rates. We studied an archaeological ancient quarry of grinding wheels for oil that has been found in the Capo d\u2019Orlando inshore (Scicchitano et al., 2011). They present semi submerged circular holes in Stilo-Capo d\u2019Orlando deposits (Carbone et al., 1998). The tectonic uplift was evaluated as the difference between the observed local paleo-sea level position and the predicted sea-level curve for the same locality (Lambeck et al., 2011). The resulting uplift rates is 0.36 mm/yr (Scicchitano et al., 2011). In this area we studied also the Brolo stack. It is a metamorphic rocks emerging at 450 m from the coastline. The study led to discovery a fossils-bearing conglomerate in protected trays at 3.5 m a.s.l.. Radiocarbon analysis on a gastropod, gave us an age of 4965 years +-70 cal BP. If we compare this data with the predicted local sea level curves (Lambeck et al., 2011), we obtain an uplift rate about 1.5 mm/yr (Lo Presti et al., 2010), which is higher than that calculated in the study of archaeological rest. A detailed study of Brolo sector show us different morphological coastline position of Brolo plain. A picture of the year 1847 shows the coastline about 200 m landward. In Brolo coastal plain we have also found a Spondylus at -6 m b.s.l. We wait for the radiocarbon dating which allows us to have a new uplift rate data. The analysis of marine geology data (Multibeam) evidenced structures connected to different faults systems, such as the submarine canyons that are the continuation of river beds. Multibeam data evidenced also tilted NE-ward submerged surfaces, indicating existing structural movements, interesting only restricted areas. So, very different uplift rates in the Holocene in very close areas distant only about 10 kilometers: both 0.36 mm/yr (Scicchitano et al. 2011) and 1.5 mm/yr (Lo Presti et al. 2010), and morphobathymetric data (tilted surfaces), evidence the important role of active tectonic lineaments. Seismic reflection profiles support this assumption, showing the metamorphic basement strongly dissected by high-angle faults, which at place determines the occurrence of emergent rock bodies (e.g. the Brolo stack). All this suggesting the occurrence of \u201crestricted regions\u201d in the coastal-marine sector with different geological behavior as response to prominent tectonic releasing bands, determining their horizontal and vertical movements
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