4,762 research outputs found

    Spatial analysis of road crashes involving vulnerable road users in support of road safety management strategies

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    On urban road networks, approximately 2 out of 3 fatalities involve pedestrians, cyclists and motorcyclists, collectively referred to as “vulnerable road users” (VRU) due to their insufficient physical protection in the event of a collision. For a safer and more sustainable road transportation system, adequate protective countermeasures need to be introduced for this user category. However, related (and limited) resources restrict any safety improvements to certain high-risk sites with elevated rates of road traffic collisions. This study reports the results of a spatial distribution analysis of traffic collisions involving VRU in Turin over the period 2006-2016. The traffic road collisions database from the Italian National Institute of Statistics (ISTAT) was used for this purpose. Crash data were firstly geo-localized, and then analyzed using Geographic Information System technologies. A cluster analysis and a Kernel Density estimation were used to build spatial patterns of crashes involving VRU. Hazardous sites were identified on a metropolitan scale. Incorrect estimates of the actual collision frequency, which are typical of studies conducted over short periods, were avoided by considering only those sites where collision rates remained significantly high throughout the entire observation period (eleven years). The results show that clusters occur at intersections, many of which are located along corridors affected by heavy traffic flows and wide cross-sections. A further analysis was conducted to explain the role played by the geometric configuration (layout) of most hazardous sections and intersections in the level and severity of injuries and fatalities

    Torsion free groups with indecomposable holonomy group I

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    We study the torsion free generalized crystallographic groups with the indecomposable holonomy group which is isomorphic to either a cyclic group of order ps{p^s} or a direct product of two cyclic groups of order p{p}.Comment: 22 pages, AMS-Te

    Traffic crash pattern modification as a result of a 30 km/h zone implementation. A case study in Turin (Italy)

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    The strategy of 30 km/h zones, referred to in the international context as "traffic calming" measures, serves to safeguard pedestrians, cyclists and motorcyclists, collectively referred to as “vulnerable road users” (VRU). Its main function is to compel drivers to observe a maximum speed limit of 30 km/h. However, urban infrastructure transformations modify traffic collision patterns and the involvement of road users, with a spatial temporal redistribution of events. This work seeks to study the effects on collision distribution resulting from the introduction of a 30 km/h zone to the Mirafiori Nord area in the city of Turin in late 2008. Collision frequencies, based on data provided by the Italian National Institute of Statistics (ISTAT), were evaluated over the period 2006-2016. Road traffic collisions involving both VRU and motorized users (“noVRU”) were taken into account. Decreases in collision frequency were found for noVRU related crashes, while the VRU crash rate remained essentially unchanged with only minor fluctuations consistent with the regression to the mean phenomenon. The countermeasures, which sought to protect VRU, were however very effective for noVRU. As the effects of each structural modification spill over into neighboring areas, the analysis of collision frequency was extended to a study area greater than the one in which the 30 km/h zone was realized. In fact, due to the migration of events, the reduction in the collision frequency in the speed restricted zone was accompanied by an increase in the same frequency in the immediate surrounding area

    Circularity Indicators as a Design Tool for Design and Construction Strategies in Architecture

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    This study addresses the challenges and barriers associated with the implementation of circular economy principles in architectural design and construction practices. It highlights the fragmented knowledge and lack of a unified approach to circular design as a major obstacle hindering the adoption of circularity. The existing frameworks for assessing circularity, such as the Material Circularity Indicator (MCI) protocol and the Level(s) assessment protocol, are applied to two projects with a high degree of deconstruction to understand their applicability in the architectural design process and identify their limitations. The study emphasises the significance of considering structural connectivity and circularity strategies during the concept-design stage, advocating for the incorporation of circularity at various scales beyond the microscale of materials. Furthermore, it emphasises the need for early implementation of Design for Disassembly (DfD) strategies on circularity scoring to enable meaningful comparisons of alternative designs using circularity metrics. The findings reveal the variability of circularity indicators based on the hierarchy of disassembly and highlights an early-stage design approach to deconstruction strategies to achieve circularity in architectural design. Overall, this study upscales the significance of a comprehensive and integrated approach to circularity in architectural design practices

    The stripping of a galaxy group diving into the massive cluster A2142

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    Structure formation in the current Universe operates through the accretion of group-scale systems onto massive clusters. The detection and study of such accreting systems is crucial to understand the build-up of the most massive virialized structures we see today. We report the discovery with XMM-Newton of an irregular X-ray substructure in the outskirts of the massive galaxy cluster Abell 2142. The tip of the X-ray emission coincides with a concentration of galaxies. The bulk of the X-ray emission of this substructure appears to be lagging behind the galaxies and extends over a projected scale of at least 800 kpc. The temperature of the gas in this region is 1.4 keV, which is a factor of ~4 lower than the surrounding medium and is typical of the virialized plasma of a galaxy group with a mass of a few 10^13M_sun. For this reason, we interpret this structure as a galaxy group in the process of being accreted onto the main dark-matter halo. The X-ray structure trailing behind the group is due to gas stripped from its original dark-matter halo as it moves through the intracluster medium (ICM). This is the longest X-ray trail reported to date. For an infall velocity of ~1,200 km s-1 we estimate that the stripped gas has been surviving in the presence of the hot ICM for at least 600 Myr, which exceeds the Spitzer conduction timescale in the medium by a factor of >~400. Such a strong suppression of conductivity is likely related to a tangled magnetic field with small coherence length and to plasma microinstabilities. The long survival time of the low-entropy intragroup medium suggests that the infalling material can eventually settle within the core of the main cluster.Comment: 11 pages, 7 figures, accepted for publication in A&

    Electron beam transfer line design for plasma driven Free Electron Lasers

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    Plasma driven particle accelerators represent the future of compact accelerating machines and Free Electron Lasers are going to benefit from these new technologies. One of the main issue of this new approach to FEL machines is the design of the transfer line needed to match of the electron-beam with the magnetic undulators. Despite the reduction of the chromaticity of plasma beams is one of the main goals, the target of this line is to be effective even in cases of beams with a considerable value of chromaticity. The method here explained is based on the code GIOTTO [1] that works using a homemade genetic algorithm and that is capable of finding optimal matching line layouts directly using a full 3D tracking code.Comment: 9 Pages, 4 Figures. A related poster was presented at EAAC 201

    Reactions between 1-Methyl-2-phenyl-3-nitrosoindole, Activated with Benzoyl Chloride, with Indole and Indolizine Derivatives as Nucleophiles: a Case of 1,3-Migration.

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    2-Phenyl-3-nitrosoindole activated with PhCOCl reacts with indoles and indolizines (NuH) affording products of 1,2-addiction which undergo 1,3-nucleophilic migration in acid media

    Different protein source (soybean or faba bean) in postweaning diets for Apennine and Sopravissana (Italian Merino) light lamb: slaughtering performances

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    While Apennine is an autochthonous medium-large size Italian meat sheep breed well placed in Central Italy, Italian Merino (Sopravissana) is an ancient endangered sheep breed once raised all over Central Italy and now interesting a marginal sheep farming. Due to economical problems in fattening lamb at high weights for Italian farmers (Sanudo et al., 2000; Sarti, 1992), light lamb is one of the main products in Italian meat sheep farming
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