1,968 research outputs found

    Will the Italian endemic gudgeon, Gobio benacensis, survive the interaction with the invasive introduced Gobio gobio?

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    The genus Gobio in Italy was represented by the endemic species G. benacensis. The original distribution of this species was the Padano-Venetian district, but since a long time it was introduced in central Italy. Introductions of alien species to Italy during the last 10 years brought the sudden introduction of the Danubian G. gobio. Genetic and morphological analyses revealed the extensive presence of G. gobio, which rapidly colonised several rivers in Italy causing the progressive decline of G. benacensis, which now should be considered as an endangered species. Among examined populations those found in the Tagliamento River and transplanted in the Ombrone River represent genetic reservoirs of this species which will probably disappear in northern Italy

    Minisuperspace dynamics in a generalized uncertainty principle framework

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    The minisuperspace dynamics of the Friedmann-Robertson-Walker (FRW) and of the Taub Universes in the context of a Generalized Uncertainty Principle is analyzed in detail. In particular, the motion of the wave packets is investigated and, in both the models, the classical singularity appear to be probabilistic suppressed. Moreover, the FRW wave packets approach the Planckian region in a stationary way and no evidences for a Big-Bounce, as predicted in Loop Quantum Cosmology, appear. On the other hand, the Taub wave packets provide the right behavior in predicting an isotropic Universe.Comment: 8 pages, 4 figures; to appear in the proceedings of the 4th Italian-Sino Workshop on Relativistic Astrophysics, AIP Conference Serie

    Occurrence of the scalloped ribbonfish Zu cristatus(Lampridiformes) in coastal waters of the central Tyrrhenian Sea, Italy

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    The occurrence of two individuals of Zu cristatus at 2 m depth in coastal waters of the Gulf of Castellamare (Tyrrhenian Sea, Italy) together with records of this rare pan-Oceanic mesopelagic species is reported. Analyses of two mitochondrial genes (12 s and 16 s; 936 bp) revealed a 2.6% sequence divergence between Mediterranean and Pacific (Japanese) samples of the species

    Assessment of the effectiveness of the embedded through-section technique for the shear strengthening of RC beams

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    Embedded Through-Section (ETS) technique is a relatively recent shear strengthening strategy for reinforced concrete (RC) beams, and consists on opening holes across the depth of the beam’s cross section, with the desired inclinations, where bars are introduced and are bonded to the concrete substrate with adhesive materials. To assess the effectiveness of this technique, a comprehensive experimental program composed of 14 RC beams was carried out, and the obtained results confirm the feasibility of the ETS method and revealed that: (i) inclined ETS strengthening bars were more effective than vertical ETS bars, and the shear capacity of the beams has increased with the decrease of the spacing between bars; (ii) brittle shear failure was converted in ductile flexural failure, and (iii) the contribution of the ETS strengthening bars for the beam shear resistance was limited by the concrete crushing or due to the yielding of the longitudinal reinforcement. The applicability of the ACI 318 (2008) and Eurocode 2 (2004) standard specifications for shear resistance was examined and a good agreement between the experimental and analytical results was obtained.The study reported in this article is part of the research project 'DURCOST', PTDC/ECM/105700/2008, supported by FCT. The authors wish to acknowledge the support provided by the 'Casais', Secil (Unibetao, Braga) and Sika Portugal Companies. The first author acknowledges the National Council for Scientific and Technological Development (CNPq), Brazil, for financial support for scholarship (GDE 200953/2007-9)

    Volume Holographic Optical Elements as Solar Concentrators

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    In this chapter, we investigate the possibility to realize a holographic solar concentrator by using a new photopolymeric material as recording medium. Therefore, two different configurations of holographic lenses (lenses with spherical and cylindrical symmetry) are described in terms of both recording process and optical response characterization. Finally, we propose the possibility to use this new photopolymer to realize holographic solar concentrator for space applications

    Analysis of the Tribological Behaviour of the Lubricated Contacts of a Connecting Rod Equipped with a Direct Pin Oiling Gallery

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    This paper describes a methodology for identifying a suitable design of a Direct-Pin-Oiling (DPO) gallery, drilled through the conrod shank of a high-performance internal combustion engine, to directly supply pressurized lubricant to the piston pin/small-end interface. Initially, a multibody elastohydrodynamic model is set up to analyse the tribological behaviour of conrod bearings, when considering a standard configuration employing a passive lubricating hole drilled on the top of the small-end. Then, a preliminary DPO gallery is introduced to examine how it affects the oil flows at lubricated interfaces and their tribological behaviour. The numerical results and parallel experimental evidence underline the need to modify the initial configuration of the DPO gallery and a more performing gallery design is proposed

    AdRem: An Integrated Approach for Adaptive Remediation

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    Abandoned industrial sites are generally characterized by soil and subsoil contamination. The paradigm currently employed for their remediation is “tabula rasa”, i.e., remediation of the entire site before its repurpose. However, this method is not economically, socially, or technologically sustainable: it delays the reuse of large areas, often well-connected to infrastructures, whose reuse may prevent further soil consumption. A possible solution to this problem is the application of adaptive reuse principles. This study, conducted at FULL (Future Urban Legacy Lab) in Politecnico di Torino, presents an interdisciplinary approach to spatialize, visualize, and manage interactions between reclamation and urban design for the transformation of contaminated urban areas. The core is based on a decision support parametric toolkit, named AdRem, developed to compare available remediation techniques and schematic urban design solutions. AdRem uses a 3D modeling interface and VPL scripting. Required input data are a geometric description of the site, data on the contamination status, viable remediation techniques, and associated features, and schematic urban design recommendations. A filtering process selects the techniques compatible with the site use foreseen. The output is an optimized remediation and reuse plan that can support an interdisciplinary discussion on possible site regeneration options

    Incidence of injuries and associated risk factors in a sample of Italian recreational padel players

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    BacKGrouNd: padel is a racket sport similar to tennis, which since the coVid-19 pandemic has been gaining popularity among recreational players. despite its popularity, epidemiological studies are still lacking. This study aimed to identify the prevalence of injuries among italian recreational padel players and associated risk factors. MeThodS: a questionnaire was administered to 127 recreational padel players between January 2022 to March 2022. The questionnaire consisted of questions to collect information regarding intrinsic and extrinsic factors related to padel practice, injury location, and injury typology. frequencies and proportions were calculated for variable description. Binomial logistic regression was adopted to identify potential risk factors. reSulTS: of the 127 participants, 100 (78.8%) reported having had an injury during the previous year. Such injury in most cases (37%) resulted in an absence from padel from 8 to 28 days. The most common injury locations were lower leg/achilles tendon (17.1%) and elbow (13.8%), while the most common injury typologies were tendinopathies (33.6%) and contusions (14.9%). Among the identified risk factors the amount of time played padel (3.5-5 hours/week), racket type (round), and racket weight (either not knowing or 356-375 g) resulted in an increase in the probability of occurring an injury. coNcluSioNS: recreational padel results in a high percentage of injuries. These frequently result in tendinopathies of the achilles tendon and elbow. inadequate racket characteristics and the amount of time played could contribute to an increase in injury incidence

    Demonstration of improved charge transfer in graphene/Au nanorods plasmonic hybrids stabilized by benzyl thiol linkers

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    Hybrids based on graphene decorated with plasmonic gold (Au) nanostructures are being investigated as possible materials combination to add to graphene functionalities of tunable plasmon resonance and enhanced absorption at selected wavelength in the visible-near-infrared region of the spectrum. Here, we report a solution drop-casting approach for fabricating stable hybrids based on chemical vapor deposition (CVD) graphene and Au nanorods, which are able to activate effective charge transfer from graphene. We demonstrate that CVD graphene functionalization by benzyl thiol (BZT) provides the linker to strong anchoring, via S-Au bonds, Au nanorods to graphene. Optical measurements by spectroscopic ellipsometry give evidence of the introduction of plasmon resonances at 1.85 and 2.25 eV in the Au nanorods/BZT/graphene hybrids, which enable surface enhanced Raman scattering (SERS) detection. Furthermore, an effective electron transfer from graphene to Au nanorods, resulting in an enhancement of p-type doping of graphene with a consequent decrease of its sheet resistance, is probed by Raman spectroscopy and corroborated by electrical measurements

    Surface Texturing of n- and p-Doped c-Si Using a Novel Plasma Chemical Texturing Process

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    Abstract n- and p-doped c-Si (100) are textured by a SF 6 /O 2 plasma chemical etching, under conditions avoiding ion bombardment. The study of the effects of plasma parameters on morphology and on surface reflectance of textured c-Si reveals a strong impact of silicon doping on texturing characteristics. SF 6 /O 2 plasma etches anisotropically n-type c-Si creating a square-based hillock-like morphology with a surface reflectivity of 6%. Conversely, for p-type Si, a H 2 plasma pretreatment is necessary to activate silicon etching and obtain a nano-textured surface with a reflectivity of 16%
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